Society of Petroleum Geophysicists (SPG) & Association of Petroleum Geologists (APG), Vadodara Chapter organised a technical meet on 22nd November 2019. The programme started with two thought-provoking, interactive talks on contemporary issues. The first one was delivered by Shri Jeetendra Tiku, General Manager (Geophysics) on the topic namely "Introduction to Policies governing Oil & Gas industry in India with special reference to Open Acreage Licensing Policies (OALP)". It was followed by another enlightening talk on the topic "Introduction of new technologies in Geophysical Services".

During his presentation, Mr. Jeetendra Tiku elucidated the various complexities pertaining to Important Acts & Rules Governing Hydrocarbon Exploration & Oilfield Development. He explained about Open Acreage Licensing Policy under Upstream Policy Regimes in India.

Shri Praveen Vohat presented an overview of Low frequency Passive Seismics. He also explained the acquisition gamut of LFPS including brief description about new LFPS Seismometer and also about the capability of new data acquisition system 508 XT.

All the SPG and APG members of WON Basin actively participated and benefited from the technical lectures. GGM - Basin Manager Shri H Madhavan in his address explained about the importance of such technical lectures and encouraged to conduct this type of program very often which will help enhancement of knowledge in earth science. The fraternities took this opportunity to bid farewell to Shri Matibar Singh, GGM-HGS, President, SPG, Vadodara Chapter.

The technical lecures were followed by colourful cultural programme and dinner.

In the evening, the members enjoyed a mesmerizing cultural programme, presented by an eminent dance troupe arranged from outside.

This was followed by an interactive sumptuous dinner. The technical programme was compared nicely by Ms Kanika, Programming Officer and Ms Nisha, Geophysicist (S). Vice President SPG Shri Rajesh Madan, Vice President APG Dr. A. K. Singh, Treasurer SPG Shri Rajesh Upadhyay and Secretary APG Shri Bhupendra Tauk were instrumental in making the event successful. The vote of thanks was proposed by Mr. Sanjay Kumar, Secretary, SPG, Vadodara Chapter.

The Earth Study 360 Imaging System “An Insight into the Interpretation Realm” by Dr.Raanan Dafni, Emerson-Paradigm

Mumbai Chapter of Society of Petroleum Geophysicist (SPG) had organized a technical presentation on, The Earth Study 360 Imaging System “An Insight into the Interpretation Realm” by Dr. Raanan Dafni, Emerson-Paradigm on 7th Nov 2019, at NBP Green Heights, ONGC, BKC, Mumbai. In his interactive and well appreciated presentation, Dr. Raanan highlighted the (a) overview of ES360 Imaging System, (b) benefits of full-azimuth angle-domain imaging, (c) case studies from both Indian and global data and (d) pre-stack interpretative engine, i.e. supplementary information from directional image gathers.

The EarthStudy 360® Imager (ES360 Imager) is a versatile cluster-based depthmigration that simultaneously uses the full recorded wave field within acontrolled aperture to generate amplitude preserved, multi-dimensional, subsurface angle gathers which are 3D full azimuth, directional and reflection angle gathers. The Imager provides fast, target-oriented solutions for local analysis, and can also be used for imaging ona regional scale.It supports isotropic and anisotropic models, and all types of land and marine datasets, including narrow and wide azimuth streamer acquisitions and OBC data. Recently, ES360 migration included converted rays (P to S) also.

Unlike conventional ray-based imaging methods (e.g. Kirchhoff migration), EarthStudy 360 uses a point-diffractor operator to shoot rays from subsurface grid points up towards the surface, forming an accurate system for mapping the recorded surface seismic data into the subsurface Local Angle Domain (LAD) at each image point. This procedure ensures maximum illumination of the image points from all subsurface directions and surface source-receiver locations; all arrivals are taken into account and amplitudes and phases are preserved.

Earth Study 360 directional angle gathers enable specular and diffractionimaging, resulting in simultaneous emphasis on continuous structural surfacesand discontinuous objects such as faults or small-scale fractures, karst features. Structuralattributes at each subsurface image point (e.g. dip, azimuth and specularity)can be derived directly from the directional angle gathers.The ES360 directional angle gathers from Narrow azimuth surveys are suitable for diffraction imaging of discontinuities like faults and fractures as they are directly related to migration aperture and not sensitive to acquisition geometry unlike the reflection angle gathers. The diffraction imaging results are a better way of delineating the discontinuities than traditional ways like coherence cube.

Earth Study 360 reflection angle gathers display reflectivity as a function ofopening angle and opening azimuth and are most meaningful in the vicinity ofactual local reflecting surfaces, where the reflection angles are measured withrespect to the derived background specular direction. They are used forautomatic picking of full-azimuth, angle domain residual moveouts, which together with the derived background orientations of the subsurfacereflection horizons, provide a complete set of data for anisotropic velocity modeldetermination, azimuthally-dependent analysis of residual velocity (VVAZ) or amplitude versus angle/azimuth (AVAZ), using full azimuth angle domain seismic data, in order to determine fractureintensity (strength) and orientation (direction). These fractures derived from the seismic were verified with production data, FMI logs and available micro-seismics.

Regarding the future roadmap of ES360,Dr. Raanan demonstrated the applicability of Deep Learning (DL) to automatically obtaining different types of high resolution subsurface geometrical objects. The Deep Learning method is applied to spatial windows of overlapping full-azimuth directional image gathers. The application of Principle Component Analysis (PCA) on covariance matrices applied to these data windows significantly reduces the data, where only the principle (informative) directivity components are considered. The back propagation of these classified principle components to the image domain shows clear differentiation between structural reflectors, faults and point diffractors, even in areas heavily masked by ambient and coherent noise such as acquisition footprints. This approach shows great promise in identifying subsurface structural features with high accuracy which would be highly beneficial to the interpreters.

Mr. SK Sharma, (GGM-GP), HGS-Mumbai felicitated Dr. Raanan for his fantastic presentation. Mr. CPS Rana, (GGM-GP), Vice-President, SPG, Mumbai Chapter sum up the whole presentation, mentioning the international recognition of activities of SPIC, WOB on ES360 imaging system. Enthusiastic interpreters had made a valuable interaction with Dr. Raanan about the pre-stack interpretative engine of ES360.

SPG Mumbai organised a technical session titled “Imaging and Reservoir Technology Update”on 11th October 2019 at Auditorium, NBP Green Heights, Mumbai.The session is a part of continuous and relentless efforts by SPG to share ideas and experiences to the geo-scientific community and to express & exchange views & opinions on various exploration problems in Mumbai offshore areas. The session was chaired by SPG Mumbai Chapter President Shri K V Krishnan. APG Mumbai Chapter Vice President Shri K. Vasudevan, SPG Mumbai Chapter Office bearers, Geoscientists from different G&G Companies and Students from Colleges were also present.

SPG Mumbai Chapter, President, Shri K V Krishnan emphasised the need of goodseismic imaging in exploration. He also made a point that with the advent of new technology and algorithm advancement, we should focus on robust processing sequence to bring out the difficult Mesozoic gas of Kutch Offshore.

SPG Mumbai Chapter,Secretary, Shri Anupam Sharma briefed on the 13th Biennial International Conference & Exposition scheduled to be held at Lulu Bolgatty International Convention Centre (LBICC), Kochi, Kerala, India from 23rd to 25th February 2020.

APG Mumbai Chapter Vice President Shri K. Vasudevan elaborated the exploration challenges in Western Offshore. He also said that successes in Mesozoic sandstone and Fractured /Weathered Dolerite (Intrusive) of Kutch Offshore need to be studied in detailed. The impact of processing,better imaging and reservoir technology advancement will certainly help in better understanding of these type of reservoirs.

• Processing-Imaging Technology Update- By QING XU Joint 3D Source Deghost and Designature,OBN Deblending, Demultiple,IMA,ISS, FWI, Least Square Q Migration. Processing methodology was detailed with recent advancements and with case studies.
• Reservoir Consulting Services- By ROBERT PORJESZ Introduction to reservoir modelling, 3D/Multicomponent/ 4D Inversion. Main focus of the talk was static model update using sesimc inversion results and computer assisted history matching-update of seismic derived model to match production data.
• G&G Studies (Robertson UK)- By MARK COWGILL Integrated G&G Studies from Exploration to Development & Production, Unconventional Experience and Workflows and Geotraining. The presentation highlighted the approach to digitisation and digitalisation of existing data sets, play fairway mapping, improved seismic imaging and reservoir characterization.

Qing Xu is currently the VP Geoscience, Asia Pacific, Robert Porjesz , Regional Manager, Asia Pacific and Mark Cowgill, Business Development Manager for CGG Geoscience.

SPG Mumbai Chapter, Vice President Shri C P S Rana concluded the technical session with vote of thanks.He said that focus to imbibe recent advancements in processing and world analogue vis a vis Western Offshore Basin, India should be our focus area to work upon.

Society of Petroleum Geophysicists – India, Jorhat Chapter organized a lecture on 25.07.2019 at ONGC, Jorhat on “Emerging Geophysical Technologies for Hydrocarbon Prospecting.” The talk was delivered by Shri U. S. D. Pandey ex-Executive Director of ONGC and attended by over sixty-five G & G professionals and SPG members from ONGC Jorhat.

Session started with welcome address and brief introduction about the objective of the program by President SPG India, Jorhat chapter Shri Vishal Shastri, GGM (GP). He said that such interactive sessions are noble initiatives and give an opportunity, especially to young executives, for Knowledge Sharing. He also detailed future programmes planned under the aegis of SPG-India, Jorhat Chapter that included more lectures and Geophysical & Geological field trips. Shri USD Pandey delivered his talk about ‘Emerging Geophysical Technologies for Hydrocarbon Prospecting’. The participative interaction by the house made the talk fruitful and interesting.

  Glimpses of the Programme

Shri Vijay Kumar Gokhale, CGM (Production), Asset Manager gave concluding remarks and emphasised the need of induction of new technologies to arrest the declining production and finding of new oil for sustenance of the production. The meeting concluded with vote of thanks by Shri H N Garg, Vice president, SPG-India, Jorhat chapter.

SPG-Ahmedabad Chapter organized a technical lecture on July 23rd 2019 on the topic “Basins, Their Structural Style and Play Fairways”. The lecture was delivered byProf.Jokhan Ram,former ED-Chief KDMIPE, ONGC and presently occupying the K.D Malviya Chair at Banaras HinduUniversity.

At the start, SPG Ahmedabad Chapter welcomed the distinguished speaker. The scholarly lecture dwelt at length the finer aspects of the subject on structure and tectonics, depositional systems, basin analysis and prospect evaluation.

The speaker covered all the aspects right from formation of different types of basins, various structural styles and its interpretation making use of the geological and geophysical data with example from Indian as well as Basins from across the globe. In the end play fairways were discussed with example form various fields. The event wasattended by large number of SPG members.It was a lively interactive session and was very well received by the audience.

SPG Ahmedabad chapter took pride in conducting such lecture series at regular intervals and looks forward for many more such knowledge sharing events in future.

On April 4th, 2019, the SPG Hyderabad chapter along with NGRI-SEG Student chapter organized a distinguished lecture at SB Hall, CSIR-NGRI, Hyderabad. Prof. Hermann J. Felix delivered SEG Distinguished lecture on “Sometimes it pays to be cheap – Comprehensive time-lapse seismic data acquisition”. Prof. Hermann J. Felix graduated from Delft University in 1992 and received a Ph.D. in Engineering Physics from the same university. His area of expertise is computational exploration seismology including economic and low-environmental impact (time-Lapse) acquisition with compressive sensing, data processing, and wave equation-based imaging and inversion. He developed curvelet-based denoising and match filtering, and also made several contributions to full-waveform inversion and RTM. Recently, he has been involved in developing the rank minimization technique for seismic data acquisition.

The conventional method of acquiring Seismic data requires firing seismic sources at regular intervals of time and record the pressure wavefield reflected from each interface in the earth’s subsurface with the help of receivers or sensors. Seismic surveys can either be performed at land or in a marine environment. The data recorded in the form of seismic traces, which represents the response of elastic wavefield to velocity and density contrast across the interface separating two layers as energy from the source travels to the interface and gets reflected back to the surface to be recorded by the sensors (Geophone/Hydrophones).

To obtain a highly resolved image of the subsurface, conventional imaging algorithms such as RTM requires regularly and densely sampled shots/receivers from seismic surveys. The cost of acquiring densely sampled surveys is insanely expensive, and when time-lapse is of interest, this cost increases too. To resolve the high cost of seismic Surveys, Prof. Felix and his team have developed an idea from Compressive sensing to design surveys that sample data at a cost significantly lower than conventional approaches. Compressive sensing (CS) is a new sampling paradigm that can reduce the cost of seismic surveys. This method uses the seismic source to be fired at random time-jittered compressed-in-time firing times, which is an example of simultaneous source acquisition. In this time-jittered method (in the marine environment), a single source vessel is constantly firing airguns arrays at jittered source locations and time instances with receivers recording continuously. This compresses the survey time and recovers a dense data onto a fine periodic grid with increased source sampling. This sampling method generates surveys with overlapping shot records and coarse source sampling that are subsequently separated and interpolated to finely sampled grid yielding sequentially sampled shots with improvements in spatial sampling.

To accurately recover signals acquired using Compressive sensing, the sampling matrix needs to be accurate, which implies having precise information about the acquisition geometry. In time jittered acquisition, source vessels map the survey area by firing shots at jittered time-instances, which translate to jittered shot locations for a given speed of the source vessel. Since the data acquired is sparse, it is reconstructed and recovered using the sparsity-promoting method and rank minimization technique. Sparsity- and rank-minimization have had a significant impact in many areas over the last several decades. Sparsity in certain transform domains has been exploited to solve underdetermined linear systems with applications to compressed sensing natural image denoising/inpainting, and seismic image processing, along with many other applications, including control, system identification, signal processing, and combinatorial optimization, and seismic data interpolation and denoising.

The talk was open to all the scientists and students of CSIR-NGRI and Osmania University. During the talk, the attendees asked questions, shared opinions, and especially the students were highly enthusiastic in asking questions. Next day a discussion session of two hours was held with students fo CSIR-NGRI and AcSIR. During the discussion, many students showed their work and got their doubts cleared. They also got the new insight which they can use in their research work. Prof. Felix was impressed and happy to see the kind of work students do at CSIR-NGRI. He appreciated the infrastructure and the facilities provided by the Director and the scientists to the students. He also appreciated the warm gesture he received at CSIR-NGRI.

A group photo of SPG Hyderabad chapter and SEG student chapter office bearers with Prof. Felix J. Hermann (center).

Society of Petroleum geophysicists, Ahmedabad Chapter,organized special lectures on ‘A feasibility study on Low Frequency Passive Seismic Survey at the Mansa and Jotana in Cambay Basin and Ashokenagar in MBA Basin’ by Dr. A. P. Singh, Scientist-Bfollowed by ‘Magnetotelluric study to characterize sediment thickness (including Mesozoic) and major faults in Kutch (Gujarat)’ by Dr. Kapil Mohan, Scientist-C, of Institute of Seismological Research Department of Science and Technology(ISR), on 22nd January, 2019 at Gandhinagar.Talk was graced by Dr. Sumer Chopra,Director/Scientist-Gand Dr. M. Ravi KumarDirector General, ISR.

In last several years there is an increasing interest in phenomenon of low frequency (0.5-10Hz) anomalies over hydrocarbon reservoirs. Passive Seismic Method is a geophysical method that utilizes a spectral frequency from seismic data to identify a subsurface fluid behaviour / direct hydrocarbon indicator. In thefirst talk the preliminary results of the Low Frequency Passive Seismic surveys (LFPS), which were performed in Ashokenagar#1, Jotana area and Jaguli#1 area were shown. Cityshark 24-bits recorder coupled with a Lennartz LE3d (5s) velocity sensor and Tromino 3G (10s) instruments were used for Jotana, Mansa and Ashokenagar#1,Jaguli#1 fields respectively. The results shows very distinctive V/H ratio >1.5 for Ashokenagar#1 (oil/Gas well) as compared to low value at Jaguli#1 (Dry well). Higher V/H ratios are also observed near proposed location. LFPS survey in 3D grid pattern around proposed locations may be planned for optimal positioning of location. The doublet response instead of single peak as observed in V/H ratio plots need to be critically analysed to ascertain their sources. It may lead to some additional potential zones.

In the second talkit was mentioned that Sediment thickness mapping (including Mesozoics), Delineation of Fault lines (hidden also), Deep Crustal studies and geothermal source zone mapping can be done using Magnetotellurics. Estimation of Mesozoic Sediment Thickness in Kachchh - The total area of the basin is about 71,000 sq km of which on-land area is 43,000 sq km and off shore area is 28,000 sq km up to 200m bathymetry. The basins filled up with 1550–2500m of Mesozoic sediments and 550m of Tertiary sediments in on land region and up-to 4500mof Tertiarysediments in offshore region.

Mesozoic rocks are exposed in six regions viz. Kutch Mainland, Wagad Highland, islands of Pachham, Khadir, and Bela, and in Chorar Hills.Surveyed petroleum source rock distribution in different geological time-scale suggested that more than 50% of source rocks as well as reservoir rock are found in Mesozoic sediments.

Seismological laboratory visit and live data demonstration of earthquake monitoring/ seismograms was also a new experience for all participants.

The session was very informative, interactive and suggestions were taken from the participants for more such talks to be arranged in future.The meeting concluded with vote of thanks and memento to Dr. A. P. Singh, Dr. Kapil Mohan, Dr. Sumer Chopra and Dr. M. Ravi Kumar.

Society of Petroleum Geophysicist (SPG), India, along with SEG (Society of Exploration Geophysicists, USA) and EAGE (European Association of Geoscientists & Engineers), in a first-of-its-kind collaborative initiative, organised two joint workshops on Imaging Challenges in sub-basalt and foothills, at Dehradun on Feb. 22-23, 2019. The two day event held at the Technical Interaction Center (TIC) of GEOPIC saw a total of around 165 delegates, 37 invited speakers and 30 invitees from major NOCs like ONGC, OVL, OIL, BPRL, GAIL etc. and petroleum companies from abroad, like Ecopetrol, Shell, Schlumberger, Shearwater, UK, BGP International, Volcanic Basin Petroleum Research, Oslo, V&G Exploration etc. The academia was well represented by participants from premium research Institutes in India like IIT Mumbai, IIT Kanpur, Wadia Institute of Himalayan Geology (WIHG) etc. as well as from abroad (IPGP, France, University of Grenoble Alpes).

Director (E), ONGC & Patron – SPG, India Mr A.K. Dwivedi was the Chief Guest in the Inaugural Session for the first workshop, “Sub-basalt Exploration in Asia and Pacific”, which was also graced byDr. Kalachand Sain, Director- Wadia Institute of Himalayan Geology (WIHG), Dr Nancy Jo House, former President SEG, USA and Dr Gladys Ethel Gonzalez, former President EAGE and Mr D. Purkayastha, ED-Head - EXCOM, ONGC and President SPG India. In his welcome address, Mr D. Purkayastha welcomed the guests, delegates and speakers and spoke about the relevance of the topics of the workshop particularly in the context of ‘difficult oil’. He also described the background as to how the workshops were conceived and the efforts that went behind in bringing them to fruition. Dr Nancy Jo House and Dr Gladys Ethel Gonzalez, spoke about their optimism that the workshops would live up to the expectations as envisioned and expressed their elation in endeavouring to collaborate with SPG, India for the same. Dr Kalachand Sain, hoped that the workshops would have significant takeaways for the participants.

Director (E)-ONGC Mr. A.K. Dwivedi inaugurating the first day workshop

Director (E)-ONGC delivering his inaugural address

Director (E)-ONGC and other dignitaries inaugurating the workshop proceedings

In his inaugural address, Mr. A.K. Dwivedi, emphasised how workshops such as these could be great opportunities for the geoscientific community to seek answers to many of the challenges that beset them and thanked SEG & EAGE for joining hands with SPG for the current endeavour. He also stressed that while only 7 of the 26 sedimentary basins are established as hydrocarbon bearing, lack of actual understanding of the remaining basins may be largely responsible for success being elusive elsewhere, rather than the absence of petroleum systems there. He stated that role of seismic imaging would be of central to exploration efforts in frontier areas, going forward.

Thirteen technical papers (including six keynotes) and six posters were presented in the first day’s workshop. Diverse topics were covered for sub-Basalt imaging like advanced seismic acquisition parameters designing (Wide Tow acquisition method, long offset, wide azimuth etc.); state of art processing techniques (like Tau-P domain processing, Non-Stretch mute technique, FWI etc.); Full waveform Tomography of wide angle data; Broadband processing and PSDM; Multi Physics Approach (Magnetotelluric method, CSEM, EM etc.) and so on. Different imaging challenges from various Indian basins (like Cambay, Kutch-Saurashrta, Kerala-Konkan basin) and foreign basins (like Rockall Basin, Ireland, Exmouth Plateau, UK Atlantic Margin) were discussed and possible solutions deliberated.

Director (E&D), Oil India Ltd., Dr P. Chandrasekaran inaugurated the second workshop, titled “Current Practice and Advances in Foothills imaging”, held on Feb. 23, 2019. Also present on the occasion were Dr Kalachand Sain, Director WIHG, Dr Nancy Jo House & Dr Gladys Ethel Gonzalez, esteemed representatives from SEG & EAGE respectively, besides Mr D. Purkayastha, President SPG India. In his inaugural speech, Dr P. Chandrasekaran emphasised on the importance of minimising uncertainties and risks as exploration shifts towards more and more difficult geographies and complex sub-surface geologies. He felt that the exploration community relies on seismic processing, perhaps more than any other single link in the exploration chain, to reduce those risks.
 

Mr D. Purkayastha, President SPG, India welcoming Director (E&D), Oil India Ltd., Dr P. Chandrasekaran (right);

Dr Nancy Jo House, Former President SEG presenting her keynote speech

Ten technical papers and three posters were presented in the second day workshop. Various issues were covered for Thrust Fold Belt imaging like advanced seismic acquisition parameters designing (Wide azimuth acquisition long offset, sparse spread, Single sensor acquisition etc.); state of art processing techniques (Common Reflection Surface processing (CRS), 3D Elastic FWI, Optimum datum processing, anisotropic processing etc.); integration of active and passive seismic data for robust velocity model building and so on. Various imaging issues from several Indian basins (Himalayan foreland basins, Cachar fold Belt, Asam-Arakan Basin etc.) and foreign basins (like Western Qaidam Basin, China, Foothills of Colombia, Western Papuan Fold Belt etc.) were deliberated upon.

Participants interacting in the poster session

Prof. Satish C Singh and Mr Chirag Tyagi summing up the workshop

The deliberations at the workshops were aptly and succinctly summed up by Dr Nancy Jo House (SEG), Dr Gladys Ethel Gonzalez (EAGE), Prof. Satish C Singh (IPGP, France) and Mr Chirag Tyagi (Schlumberger).

Another highlight of the Joint Workshop was a field trip for the foreign delegates to familiarise them of structural and tectonic elements of Frontal Himalayan Fold-Thrust belt in the Dehradun-Mussoorie area, which generated a lot of interest.

Faculty Dr Mohit Punia (Survey of India) showing Himalayan geological structure to the field participants (right).

SPG Mumbai Chapter organized a presentation on “State of the Art software solutions for E&P Challenges, Lithology classification & Stochastic Inversionon 19.01.2018 at ONGC, Priyadarshani, Mumbai.
On behalf of SPG Mumbai Chapter, Shri Anupam Sharma, Secretary SPG, introduced the presenter, Shri C M Jain, Vice President, welcomed the speaker.
Shri Hemant KumarDixit, from M/s CGG GeoSoftwarepresented the solution to quantitatively integrate various data typerelated to geophysics, geology, petro-physics, rock physics and generate realistic 3D numerical models of reservoir properties for flow simulation and production assessment.

Geostatistics provides a powerful framework for combining sparsely sampled high resolution well information with densely sampled but less vertical resolution 3-D seismic information. Thereby accurate estimates of reservoir properties and an assessment of the uncertainty and risks associated with reservoir models. He dealt upon one of the emerging geophysical technology, the stochastic inversion for the prediction of rock and fluid properties. The probabilistic inverse method.

The integration of stochastic inverse methods and geophysical modeling allows generating multiple reservoir models of rock and fluid properties that honour both

Seismic and wells geophysical measurements. Stochastic approach allows sampling multiple solutions from the posterior distribution of model parameters predictions. Stochastic inversion algorithms can be applied to seismic inversions problems as well as petro-physical inversion problems.

Mr Dixit presented detailed feature of LithoSI and GeoSI software modules and demonstrated improvement through few case studies.

 
 

More than sixty geoscientist attended the presentation.Shri U S D Pandey, President SPG Mumbai Chapter and Shri M Ayyadurai, ED-Basin Manager, WOB, ONGC presented and a memento to speaker. Vote of thanks was given by Mr. Anupam Sharma, Secretary, SPG- Mumbai Chapter

About speaker : Mr. HemantDixit did his post graduation with M.Tech. in Exploration Geophysics (Applied Geophysics) from the Indian Institute of Technology, Roorkee, India. He has more than fifteen years of experience working as an Interpretation and QI Geophysicist.His core expertise lies in the integration of Seismic Petro physics and Rock Physics, together with application of inversion technology for reservoir evaluation and assessment.He has served as a member in technical committee of SPG India and editorial team member of GeoHorizon magazine published by SPG-India.

Email : hemant.kumar-dixit@cgg.com
Mobile : 9930916244

SSPG, Mumbai chapterorganised a technical session. After the welcome address and brief introduction an ex-ONGCianMr S P Singh,President Global Geoscience Services in Emerson-Paradigm started presentation on “Orthorhombic Earth Modelling and Imaging the Need”on 7th Feb, 2018 at ONGC Panvel.

Mr. Singh talked about accounting anisotropy in data processing is now recognized as an important step in improving the quality of seismic data. In isotropic seismic data processing we consider a single velocity at a depth point and try to flat the gather to the maximum offset to depth ratio. But in reality the model is anisotropic, means we have different velocities at a depth point for different directions. When we try to fit this model with a single velocity, it generates well mis-tie as well as lateral mis- positioning in the migrated image. The anisotropy solution was first successfully tested in ONGC by speaker himself.

Commonly, two forms of anisotropy are considered. The first and most common is vertical transverse isotropy (VTI), or the closely associated tilted transverse isotropy (TTI). This anisotropy is often caused by fine layering of sediments, with the layering smaller in scale than the seismic wavelength. In the case of VTI the bedding planes are horizontal, while in TTI they are dipping.

The second form of anisotropy considered in P-wave processing is horizontal transverse isotropy (HTI). The most commonly considered mechanism for this type of anisotropy is vertical aligned fractures embedded in an isotropic background medium. In reality, the subsurface is likely to contain both types of anisotropy, either combined or in separate layers. An earth model with vertical aligned fractures embedded in a finely layered background is termed as orthorhombic earth model.

These type of anisotropy causes azimuthal travel-time variations which can become apparent at near-tomid-offsets (offset-to-depth ratios of 0.5 and beyond). Study of azimuthal travel-time variations is important for delineation of fracture orientations.
Mr S. P. Singh introduced the concepts of ES360 imaging of M/S. Emerson-Paradigm. He also introduced the concept of anisotropy and its need. He has explained how ES 360 Reflection gather preserves the azimuthal information which is helpful in inversion of the elastic modulus parameters needed for Orthorhombic Earth Modelling.
This knowledge sharing platform was also shared by some representatives of Regional Laboratories, Logging services, Panvel and a few superannuated ONGC personals.
This technical session was attended by more than 60 geoscientists. It was a very interactive presentation. There was a good strength of young executives amongst the audience who took keen interest and participated in interaction. The presentation concluded with a very informative question answer session.

This technical session is also attended by Shri U.S.D. Pandey, ED-CGS- President, Mumbai Chapter, Shri K. V. Krishnan, GGM-HGS and Shri C.P.S. Rana, GM-I/C SPIC

This technical session concluded with felicitation of the speaker and vote of thanks.

About speaker : Mr Shiv Pujan Singh is Director Global Technology of geophysicalservices at Paradigm Houston. His maininterests aremodelling anisotropic velocity, including HTI/orthorhombicanisotropy for identifyingfractures using P-wave seismic data andfull-azimuth image gathers, and AVA(Z)inversion for fracture mapping usingfull-azimuth gathers. He has more than 32 years of experience in the field of data processing.

Email : spsingh@paradigmgeo.com

SPG Mumbai Chapter organized a one day workshop on “Conventional cores and their application in hydrocarbon exploration and exploitation”  at Regional Geoscience Lab, ONGC, Panvel on 24.05.2018 attended by participants from ONGC, BPRL, WesternGeco/Schlumberger.

All the participants with dignitaries

​

Secretary, SPG Mumbai Chapter Shri Anupam Sharma welcomed the dignitaries Shri USD Pandey, Shri M. Ayyadurai, Dr Alok Dave, Ashwani Mishra and participants from ONGC, BPRL, WesternGeco and Schlumberger. President SPG Mumbai Chapter & ED-Chief Geophysical Services, Shri U S D Pandey in his inaugural address thanked Basin Manager for providing infrastructure to conduct this workshop at RGL, Panvel and also to Dr Alok Dave for his wholehearted support and cooperation in conducting this workshop.He stressed on the role of core studies in petroleum exploration in general and reservoir characterization throughseismic attributes in particular. He called upon the SPG Office bearer to organize more workshops. ED-Basin manager, WOB Shri M. Ayyadurai exhorted all the participants to fully utilize this golden opportunity to learn fine nuances of core usage analysis from Dr Alok Dave a veteran and teacher par excellence.

Dr. Alok Dave interacting with the participants

 

Dr Alok Dave gave a brief outline of the workshop with main focus from core to log to seismic and live interaction with rocks i.e., cores from all stratigraphic levels from basement to middle Miocene including all geological aspects relevant to exploration and exploitation. Dr Dave emphasized about the importance of coring to reduce uncertainty in reservoir evaluation by providing data representative of the reservoir at in-situ conditions. He asked all the participants to maximize advantage of this workshop by fully integrating Core studies with Geophysics, Petrophysics, Geochemistry and Reservoir Engineering.

Core samples from various formations

The day was spent in core library where all the participants had firsthand information with cores. Twelve cores were laid out from various wells of western offshore to provide insight on various sub-surface environment starting from Basement complex (for variation in Basement lithologies) to Basal clastics(for facies and environment study) to Basalt (For fractures & integration with FMI) to Panna (Paleocene Early Eocene) (For Sedimentary features and depositional environment) to Jakhau (Early Eocene) (for barrier bar complex) to Jakhau(Early Eocene) (for depositional environment, depth correction by core gamma log) to Bassein(Middle Eocene) for (for Karst and Collapse features) to Middle Eocene Early Oligocene hiatus (for Lst/LstUnconformity) to Daman (Late Oligocene) (for Forced regression) to Early Miocene & Bombay (Early Miocene) (for High resolution T/R cycles in Carbonates) to Middle Miocene (For deep water contourites).

During the concluding session Shri Rana, Head-SPIC, GPS thanked Dr Dave and team for this wonderful workshop and enlightened the house. Secretary, SPG Mumbai chapter Shri Anupam Sharma gave takeaways of workshop and thanked everyone who have contributed for the success of the workshop. In the end Shri R D Chowdhary proposed vote of thanks to one and all.

The title of the talk was “Geomechanical Modelling – Data to Solutions (Nearby Wellbore & Field-Scale)”. It was given by Somesh Bahuguna, Drilling and Geomechanics Team Leader from Schlumberger to an audience of Geoscience personnel of varied seniority and expertise. The talk was attended by Sri Debashish Basu Asset Manager, Ahmedabad Asset and Sri O.N.Gyani Head of Institute, IRS.

The presentation started by a discussion on what is geomechanics and what kind of challenges does it addresses to within the Oil and Gas Industry. It was followed a small recapitulation of basics rock mechanics and intrinsic properties like Poisson’s ratio, Young’s Modulus and extrinsic properties like Horizontal stresses, Overburden stress etc.

Speaker being welcomed by O.N. Gyani ,HOI,IRS Talk in progress

In order to provide geomechanics based solution, a Mechanical Earth Model (MEM) is a basic requirement. Hence, presentation described what a 1D is and 3D MEM and what are its various components. What log measurements are required to generate each MEM component was also discussed.

Further part of the presentation was divided into two parts 1D Solution and 3D solutions and relevant case studies. Under both the headings solutions like Drilling solutions using Pore pressure and Wellbore stability modelling, Sanding Analysis, Critical Stressed Fracture analysis for Basement reservoirs, Hydraulic Fracture optimization in tight reservoirs. Of these topics, Hydraulic Fracture optimization was discussed in detail. Importance of Isotropic Stress Model and TIV Anisotropic stress model with regards to laminated reservoirs was discussed.

It was shown how the latter allows for generation of more realistic simulation using stress models which allows proper fracturing job and ideal placement of proppants.

Geoscientists attending the talkAM,Ahmedabad & HOI,IRSpresenting the momento

The 3D phase of the presentation started with basic requirements of 3D MEM construction. Concept of coupling of stress model and dynamic pressure model was also discussed. Examples of how coupling allows for estimation of reservoir compaction and surface subsidence were presented along with some case studies. In this context, effect of depletion on reservoir permeability was also discussed along with some case studies. Hydraulic Fracture optimization using 3D numerical modelling was also discussed in detail. Importance of software packages which allow for generation and seamless integration of Static modelling, Stress modelling, Dynamicmodelling and Hydraulic fracture stimulation using numerical algorithms was also discussed.

The talk ended with a Q&A session where audience took active part in the discussion and brought forward their challenges and their experience in dealing with it.

Association of Petroleum Geologists (APG) and Society of Petroleum Geophysicists (SPG), Kolkata Chapter jointly conducted a technical session on 19 March 2018 with the theme “Major Gondwana Basins of India- Problems and Prejudices”. This technical session was attended by all the APG and SPG members of Kolkata Chapter and distinguished retired dignitaries.

Recently the focus of exploration is emphasizing the search for Coal Bed Methane (CBM) and Shale Gas in the Gondwana sequences of the Sedimentary basins of India in addition to exploration of Conventional Hydrocarbon. Hence the technical session was organised to address the various issues related to the exploration of Conventional hydrocarbon, Coal Bed Methane and Shale Gas in Indian sedimentary basins. The lecture was delivered Prof. Dhurjati Prasad Sengupta, Dept. of Geological Sciences, Indian Statistical Institute, Kolkata as an Industry-Academia interaction.

Shri C Mahapatra welcoming Prof. D P Sengupta

ED-Basin Manager and patron APG & SPG Kolkata ChapterProf. D P Sengupta delivering the lecture

Prof. D P Sengupta is an eminent Bio stratigrapher in Dept. of Geological Sciences, Indian Statistical Institute,Kolkata. He has rich experience in the domain of Biostratigraphy of Lower and Upper Gondwana sequences of Indian Basins. He has been working on Gondwana stratigraphy and vertebrate palaeontology with interests inmorphometrics and shape analysis of fossil vertebrates. He has carried out extensive research work; mainly field based on Gondwanas of India and abroad and has erected many new vertebrate taxa and used metamorphic techniques for the first time on Indian Gondwana vertebrate.

The session started with brief presentation about the activities and future plans of APG & SPGKolkata Chapter by Joint Secretary, APG, Kolkata Chapter, Mr G C Deb, DGM (G) and Secretary, SPG, Kolkata Chapter, MrP K Bose, DGM (GP) respectively followed by the lecture & presentation by Prof. D P Sengupta.

The Brief Synopsis of the talk is as follows:

The Gondwana deposits of peninsular India are revisited with the light of new information and ideas. The Gondwana sediments of peninsular India rest on Pre-Cambrian basement and the early Paleozoic deposits are absent in the peninsular part. Some problems and prejudices are inherent to the Indian Gondwanas.

Traditionally, the Gondwana starts with a glacial to fluvio-glacial and glacio-marine Formation called the Talchir. Whether Talchir starts from Carboniferous or Permian-- is the initial question which still remains debatable. The coal regime that followed Talchir is present in all the Permian Gondwana deposits of the southern continents of the world. In fact, the glacial and coaly part with characteristics of Glossopteris-Gangamopteris flora are present in all the Gondwana deposits of India, Australia, Antarctica, South Africa and Argentina.

However, the Triassic ‘Red bed’ that followed Coal-shale-sandstone deposits is not at all restricted in Gondwana. It is a global phenomenon with a global flora and fauna. Continental Triassic sediments, at different parts of peninsular India, differentially fill up the initial rift system that created the Gondwana basins. They also have different fault patterns and sediment loads. Thus, they are not uniform and difficult to correlate among different Gondwana basins of India. On the other hand, overall characteristic lithology (Red Mudstone), flora and particularly, the universal terrestrial fauna make the correlation of Triassic red beds easier in global scale. Thus, during Triassic, Gondwana lost its character as “restricted rift deposits in southern continents”. This creates a problem whether to include Triassic part within Gondwana or not.

In case of the non-marine Jurassic, the story is different for peninsular India. There are very few non-marine Jurassic litho-formations in peninsular India. Most of Indian Jurassics (Peninsular) are marine.

Similarly, in Cretaceous, non-marine sediments of Satpura and that of a small part of Pranhita-Godavari basin, are directly overlying the Gondwanas. Other so called “Cretaceous upper Gondwana” sediments are lying on different basements, but not on Gondwana. They are lithologically different from typical Gondwanas. The flora of Jurassic and Cretaeous, the typical “upper Gondwana flora” is actually a global flora that happened to be present in the “upper Gondwana”.

With all these doubts and indecisive evidences mentioned above, Indian Gondwanas, are still thought to be unified successions with a span of Carboniferous to Cretaceous. However, this concept needs serious rethinking.

President, APG, Kolkata Chapter, Mr. S K Das President, addressing the gathering

SPG, Kolkata Chapter, Mr. S Chakraborty addressing the gathering

APG Jt. Secretary Mr G.C Deb briefing activities of SPG APG, Kolkata Chapter

Secretary Mr P K Bose briefing activities of SPG, Kolkata Chapter

The technical session ended with the concluding remarks of ED-Basin Manager, MBA Basin Kolkataand Patron APG & SPG Kolkata Chapter, Shri ChakradharaMahapatra. He opined that Industry-Academia interaction of such nature is very helpful for ONGC in the long run and more such talks can be organised in future. He urged the participants to discuss and debate ideas, policies& strategies that would allow more comprehensive exploration of the region so as to conclude in a more definitive manner about this region. He also complimented all the SPG and APG members, Kolkata Chapter for organising this technical session.

APG & SPG members, Kolkata Chapter participating in the Techical Session

APG & SPG Patron, Kolkata Chapter Shri C. Mahapatra concluding the sesion

The session was compered by Ms.Supriya Shukla, Sr. Geophysicist(S), member SPG, Kolkata Chapter and concluded with vote of thanks by Mr.Arun Debasis, Sr. Geologist, member APG, Kolkata Chapter.

Member,SPG Kolkata Chapter, Ms. Supriya Shukla compering the sesion

Member,APG Kolkata Chapter, Mr. Arun Debasis offering vote of thanks