Verified email at iitism.ac.in
Assistant Professor; Department of Applied Geophysics
Indian Institute of Technology (Indian School of Mines), Dhanbad
10 years of Oil and Gas industry experience as a reservoir geophysicist. At present working as faculty with exploration seismic and reservoir geophysics specialization.
Computational Geophysics, Quantitative And Qualitative Seismic Interpretation, Reservoir Characterization, Rock Physics Analysis, Seismic Inversion, Geo-Cellular Modeling, 4D And Passive Seismic Analysis, Study On CBM And Carbonate Reservoir, Study On Unconventional Energy Sources, Carbon Capture And Storage (CCS) For Oil And Gas Reservoir
Saurabh Datta Gupta, Sugata Kumar Sinha, and Raman Chahal
Journal of Petroleum Exploration and Production Technology, ISSN: 21900558, eISSN: 21900566, Pages: 1919-1943, Published: July 2022 Springer Science and Business Media LLC
AbstractThe Rajasthan basin situates in the western part of India. The basin architecture comprises three significant sub-basins such as Barmer-Sanchor, Bikaner-Nagaur and Jaisalmer. Barmer-Sanchor and Bikaner-Nagaur sub-basins are intracratonic categories, whereas the Jaisalmer sub-basin comes under intracratonic nature. The current study was conducted in the Jaisalmer sub-basin. The study was conducted in two regions in the Jaisalmer sub-basin through a comparative quantitative interpretation study with the help of two vintages seismic surveys. Ghotaru and Bandha are two adjacent areas in the Jaisalmer sub-basin where Ghotaru has seen few hydrocarbon discoveries; however, no such discoveries are encountered in the Bandha area. The current study was concentrated on the Jaisalmer limestone formation in the Jurassic age. The sub-basin and its related study area have been structurally deformed due to various tectonic activities. Structural deformation was played a crucial role in changing the rock property of limestone facies. A post-stack seismic inversion was carried out to capture the rock property changes in the limestone reservoir based on P-impedance values. Development of high P-impedance was observed in the Ghotaru region compared to the Bandha region from this study. A frequency changes of the limestone lithofacies with structural components was also captured in this study. The high impedance limestone lithofacies is a probable hydrocarbon-bearing reservoir unit in the Jaisalmer Formation of the Ghotaru region.
Priyanka Gautam and Saurabh Datta Gupta
Journal of Applied Geophysics, ISSN: 09269851, Volume: 201, Published: June 2022 Elsevier BV
S. P. Vijay Kumar, S. Ganesh Kumar, and Saurabh Datta Gupta
Bulletin of Earthquake Engineering, ISSN: 1570761X, eISSN: 15731456, Pages: 1397-1429, Published: February 2022 Springer Science and Business Media LLC
Occurrence of earthquake generates both horizontal and vertical ground motions. In saturated sands, combination of generated ground motions and pore water pressures induces soil liquefaction. In this study, a composite skirted ground reinforcement system was developed to mitigate generation of pore water pressure in liquefiable soils and also to attenuate incoming ground motions to the foundation. The composite system contains Polyurethane foam as an isolation barrier for ground motion attenuation with stone columns for improving both soil densification and drainage. The performance of this composite reinforcement system was evaluated under repeated acceleration loading conditions to estimate its efficiency. For testing, saturated ground model having 40% and 60% relative density was prepared and investigated with and without the composite reinforcement system. Test results showed that, the developed skirted ground reinforcement system effectively mitigates the interaction of incoming ground motions with the foundation and also improves the reliquefaction resistance of soil compared to that of unreinforced ground.
Himalayan Geology, ISSN: 09718966, Pages: 471-489, Published: 2022
Journal of Petroleum Science and Engineering, ISSN: 09204105, Volume: 201, Published: June 2021
Pydiraju Yalamanchi and Saurabh Datta Gupta
Pure and Applied Geophysics, ISSN: 00334553, eISSN: 14209136, Volume: 178, Pages: 1825-1844, Published: May 2021 Springer Science and Business Media LLC
The frequent variability of petrophysical properties makes hydrocarbon exploration challenging in carbonate reservoirs. Nowadays, quantitative interpretation (QI) is an essential part of hydrocarbon exploration in a complex reservoir, which needs adequate rock physics data at the well level. However, sometimes the relevant data are not available in earlier discovered oil and gas fields. We observed that the old oil and gas fields in the onshore parts of India have a scarcity of density and compressional velocity (Vp) data at the well level. Gardner's empirical expression provides the scope to estimate Vp from acquired density data and vice versa. However, there are two constants in this relationship, and these are different for different saturation cases of the reservoir due to different mineralogical content in the reservoir rock. The current study aims to identify suitable rock mineral mixing methods and their related uncertainty for estimating Gardner's constants. This uncertainty leads to the estimation of the degree of unwanted flexibility for Vp measurement. Improper selection of the rock mineral mixing method generates uncertainties during the fluid substitution model, mainly where available data are limited. A machine learning (ML) approach based on the naïve Bayes algorithm was adopted in this study to select the appropriate rock mineral mixing method from a limited data set. The study was performed in a carbonate reservoir in an onshore sedimentary basin of western India. The ML study shows that the Reuss rock mineral mixing method is suitable for the computation of Gardner's constant in different saturation models for this carbonate reservoir, with less uncertainty.
Raman Chahal and Saurabh Datta Gupta
Petroleum Science, ISSN: 16725107, eISSN: 19958226, Pages: 1556-1578, Published: December 2020 Elsevier BV
AbstractGeoscientific evidence shows that various parameters such as compaction, buoyancy effect, hydrocarbon maturation, gas effect and tectonic activities control the pore pressure of sub-surface geology. Spatially controlled geoscientific data in the tectonically active areas is significantly useful for robust estimation of pre-drill pore pressure. The reservoir which is tectonically complex and pore pressure is changing frequently that circumference motivated us to conduct this study. The changes in pore pressure have been captured from the fine-scale to the broad scale in the Jaisalmer sub-basin. Pore pressure variation has been distinctly observed in pre- and post-Jurassic age based on the current study. Post-stack seismic inversion study was conducted to capturing the variation of pore pressure. Analysis of low-frequency spectrum and integrated interval velocity model provided a detailed feature of pore pressure in each compartment of the study area. Pore pressure estimated from well log data was correlated with seismic inversion based result. Based on the current study one well has been proposed where pore pressure was estimated and two distinguished trends are identified in the study zone. The approaches of the current study were analysed thoroughly and it will be highly useful in complex reservoir condition where pore pressure varies frequently.
Sugata Kumar Sinha and Saurabh Datta Gupta
Journal of the Geological Society of India, ISSN: 00167622, eISSN: 09746889, Pages: 298-307, Published: 1 September 2020 Springer Science and Business Media LLC
The coal formation of the Damodar basin is found in parts of the Indian states of West Bengal and Jharkhand. However, the potentiality of the coal formation and its presence across the basin are not equal. Both East Bokaro and West Bokaro are highly fertile and productive for high-quality coal. However, due to the lack of coal seams, no significant discoveries can be made between these two regions. The purpose of the present study is to identify the reasons for the lack of coal seam between the areas of the eastern and western Bokaro of the Damodar basin. The study area was chosen near the Lugu hill, adjacent to the Ghato area in the West Bokaro based on the geological significance. The presence of the coal seam is not identified in the study area. To reach the objective of the study an integrated geological model was developed based on laboratory analysis, computational and analytical approach. Newly acquired shallow seismic data, earlier acquired digitized gravity data and drilled well data were used for the study. Rock samples were collected from discrete areas of the Lugu hill for laboratory analysis. The integrated geological depositional model suggests that crustal thinning and basement upliftment is the significant reason for the absence of coal seam in between East and West Bokaro. Several tectonic activities and associated intrusion are another factor for the absence of coal in the area.
Nabanita Pradhan, Saurabh Datta Gupta, and P R Mohanty
Journal of Earth System Science, ISSN: 23474327, eISSN: 0973774X, Volume: 128, Published: 1 December 2019 Springer Science and Business Media LLC
Measurement of velocity anisotropy is an essential parameter for capturing the heterogeneity of sub-surface geology to characterise the hydrocarbon-bearing reservoir. The incorporation of velocity anisotropy parameters during the preparation of the 3D velocity model represents a robust result in a challenging geological set-up during interpretation. Generally, we can observe that the shale formation is more sensitive to velocity anisotropy response in comparison with other formations such as sandstone, siltstone for clastic reservoir or limestone and dolomite for carbonate reservoir. This study was performed mostly in the high amount shale section mixed with limestone and claystone of the Jaisalmer sub-basin area which lies in the western part of India. The preparation of the velocity model for frequent changes of lithology in the clastic and carbonate reservoir is challenging due to several changes of velocity which show a limitation in the result of the gridded velocity model. The objective of this study is to capture the changes of compressional and shear wave velocity in mixed lithology of the significant shale formation. The idea was due to the inclusion of the anisotropy incorporated changed velocity during the preparation of the gridded velocity model for correctly identified lithology. The shale formation which is the zone of investigation of the current study is situated over a carbonate sequence, and an estimated velocity anisotropy factor of this shale formation will contribute significantly during the cumulative study of velocity modelling of all formation. The current study shows that shale formation shows the character of orthorhombic anisotropy; however, this study was performed based on significant changes of well log data and related effects of vertically transverse isotropic parameters of the shale formation. The fundamental Thomsen anisotropy parameters were estimated by capturing the deviation of five independent stiffness coefficients. Significant changes in evaluated shale velocity were observed after the incorporation of the estimated Thomsen parameter in velocity values.
Saurabh Datta Gupta and Ramesh Gupta
Journal of the Geological Society of India, ISSN: 00167622, eISSN: 09746889, Pages: 485-494, Published: 1 October 2017 Springer Science and Business Media LLC
Cambay basin is an intra-cratonic rift graben formed as a result of rifting which was occurred in late Cretaceous with Deccan lava eruption through linear trending NNW to SSE directional basin. The Deccan basalt forms the basement over which more than 7–11 km thick piles of Tertiary sediments have been deposited during syn-rift and post-rift phases of basin development. Cambay basin has been considered as one of the significant hydrocarbon prolific basin in India. The biggest challenge in current days for this basin is further exploration or exploration under development stage in small marginal field or unexplored left out areas in the basin part as most of the areas are already explored/discovered by various small to big E&P (exploration & production) industrial players. In this present study one such small marginal field has been chosen for “Exploration under Development” portfolio in mid Cambay basin. The amount of oil-in-place volume, investment and techno-economics analysis of small marginal field has made this study area. In view of further hydrocarbon exploration in this area this kind of study will provide a robust support in limited dataset. The reservoir sand quality of the study area is discrete, thin and less permeable. This kind of sand body detection through classical seismic interpretation approach is difficult and there will be always a big amount of uncertainties for findings the pay reservoir sand. In view of the limitation of available data and challenging geological setup of the reservoir, a quantitative approach has been taken to detect the thin reservoir sand in this study area. Primarily coloured inversion technique has been applied on post-stack seismic data based upon well to seismic correlation and reservoir sand detection in seismic interpretation and well log property analysis. This technique has produced higher detectability impedance/property volume with respect to normal post-stack seismic data signature. Based on high contrast impedance/elastic property further seismic based attribute analysis on reservoir section has been performed. The attribute analysis has been made along surface and 3D seismic data level, provided clear image about the thin hydrocarbon sand reservoir. Based upon quantitative interpretation approach coloured inverted volume the prospect was chosen for further drilling in the study area and drilling of that sand was turned to be a hydrocarbon discovery prospect. The unconventional approaches e.g. coloured inversion with limited dataset for this kind of small marginal field has potential to find the hydrocarbon.
Rima Chatterjee, Saurabh Datta Gupta, and Partha Pratim Mandal
Journal of the Geological Society of India, ISSN: 00167622, eISSN: 09746889, Pages: 573-580, Published: 1 May 2017 Springer Science and Business Media LLC
The Deccan trap basalt, laid down by multiple lava flows during upper Cretaceous to Paleocene times forms the basement of current study in Cambay basin. As such, there is great interest and value in fracture detection and evaluation of fractured basement reservoirs in the Cambay basin. The procedure for identification and evaluation of natural as well as induced fractures in basaltic basement of the Cambay basin is presented in this work. In this study formation micro-imager (FMI) and extended range micro-imager (XRMI) log data for fracture identification is used. The Deccan trap basaltic basement of the study area, comprising five wells in the Tarapur-Cambay block, has potential for holding commercial hydrocarbon due to the presence of fractures and weathered basement. Both image logs (FMI, XRMI) identify three types of fracture including open (conductive), partially open and closed (resistive) fractures, of which open and partially open fractures are important for hydrocarbon accumulation. Fracture dip ranges from 10° to 80°. Image logs have also identified washout, breakout and drilling-induced fracture zones. The strike direction of the open natural fractures for four wells varies from N60°E to N30°E whereas the strike direction of most natural fracture in the fifth well is oriented towards N20°W. The orientations of drilling-induced fractures and breakouts may be interpreted for the in-situ stress direction over the logged interval. Drilling-induced tensile fractures, identified over the depth interval of 1969–1972 m, and borehole breakouts over the interval of 1953–1955 m in one well, suggest an orientation of maximum in-situ horizontal compressive stress (SH) lies in the north-south direction. The azimuths of open natural fractures in the same well vary from north-south to N30°E. It is expected that the direction of fluid flow will be controlled by open natural fractures and therefore would be in a direction parallel to the SH direction, which is orthogonal to the minimum horizontal stress (Sh) direction. The orientations observed are consistent with the present day SH direction in the study area of Cambay basin.
Rima Chatterjee, Saurabh Datta Gupta, and M.Y. Farroqui
Journal of Petroleum Science and Engineering, ISSN: 09204105, Volume: 109, Pages: 87-95, Published: September 2013 Elsevier BV
Abstract Full stack seismic data in Cambay basin, India, shows limited contrast between sandstone reservoirs and other lithologies. The seismic inversion result has been used here to convert the seismic reflection data into impedance log at each point and the ratio of every point. Wavelet estimations have been carried out for four wells namely, AM-11, AM-12, AM-13 and AM-14 lying between Sanand and Nawagam oilfields located in the Ahmedabad–Mehsana block of Cambay basin. The combination of P-impedance and compressional wave velocity (Vp) to shear wave velocity (Vs) ratio has been used to delineate the pay sand. Reservoir pay sand in Eocene pay formation has been delineated from these wells. The cross plotting technique between Vp/Vs (from four wells AM-11 to AM-14 under the study area) and P-impedance values has differentiated sand and shale. It is observed that the high P-impedance sand is associated with low porosity (15–18%) values while the low P-impedance sand is associated with relatively high porosity (20–25%) values.
Rima Chatterjee, Saurabh Datta Gupta, and M Y Farooqui
Journal of Geophysics and Engineering, ISSN: 17422132, eISSN: 17422140, Pages: 784, Published: December 2012 Oxford University Press (OUP)
Rima Chatterjee, Saurabh Datta Gupta, and M Y Farooqui
Journal of Geophysics and Engineering, ISSN: 17422132, eISSN: 17422140, Pages: 595-610, Published: October 2012 Oxford University Press (OUP)
Low-resistivity pay sands have been identified in four wells, namely: AM-7, AM-8, TA-1 and TA-5, which penetrate the Eocene pay-IV (EP-IV) sand unit of the Kalol formation in the Cambay basin. These wells are located near the Dholka and Kanwara oilfields in the Cambay basin. The main objective of this paper is to evaluate nuclear magnetic resonance (NMR) logs of the low-resistivity reservoirs from these four wells and to determine the petrophysical properties more accurately than conventional logs have done. The thickness of low-resistivity sand varies from 5 to 17?m in the wells under the study area. The formation has been characterized by a high surface area; thus irreducible water saturation (Swi) is high. The resistivity of these pay zones varies from 1 to 8 ?m and the total NMR porosity ranges from 15% to 50%. The free fluid porosity ranges from 2% to 5% in wells TA-1 and TA-5 and 12?20% in wells AM-7 and AM-8. The Timur?Coates/SDR model derived that the permeability of the low-resistivity reservoir ranges from 0.8 to 1.5 md in wells TA-1 and TA-5 and 10?110 md in wells AM-7 and AM-8.
Saurabh Datta Gupta, Rima Chatterjee, and M. Y. Farooqui
International Journal of Earth Sciences, ISSN: 14373254, eISSN: 14373262, Volume: 101, Pages: 1407-1426, Published: July 2012 Springer Science and Business Media LLC
The Cambay Basin is 450-km-long north–south-trending graben with an average width of 50 km, having maximum depth of about 7 km. The origin of the Cambay and other Basins on the western margin of India are related to the break up of the Gondwana super-continent in the Late-Triassic to Early-Jurassic (215 ma). The structural disposition of the Pre-Cambrian basement—a complex of igneous and metamorphic rocks exposed in the vicinity of the Cambay Basin—controls its architecture. The principal lineaments in the Basin are aligned towards NE-SE, ENE-WSW and NNW-SSE, respectively. Rock physics templates (RPTs) are charts and graphs generated by using rock physics models, constrained by local geology, that serve as tools for lithology and fluid differentiation. RPT can act as a powerful tool in validating hydrocarbon anomalies in undrilled areas and assist in seismic interpretation and prospect evaluation. However, the success of RPT analysis depends on the availability of the local geological information and the use of the proper model. RPT analysis has been performed on well logs and seismic data of a particular study area in mid Cambay Basin. Rock physics diagnostic approach is adopted in the study area placed at mid Cambay Basin to estimate the volume in the reservoir sands from 6 wells (namely; A, B, C, D, E and F) where oil was already encountered in one well, D. In the study area, hydrocarbon prospective zone has been marked through compressional (P wave) and shear wave (S wave) impedance only. In the RPT analysis, we have plotted different kinds of graphical responses of Lame’s parameters, which are the function of P-wave velocity, S-wave velocity and density. The discrete thin sand reservoirs have been delineated through the RPT analysis. The reservoir pay sand thickness map of the study area has also been derived from RPT analysis and fluid characterization. Through this fluid characterization, oil-bearing thin sand layers have been found in well E including well D. The sand distribution results prove that this methodology has able to perform reservoir characterization and seismic data interpretation more quantitatively and efficiently.
Society of Petroleum Engineers - International Petroleum Technology Conference 2012, IPTC 2012, Pages: 1960-1973, Published: 2012
Saurabh Datta Gupta, Rima Chatterjee, and M Y Farooqui
Journal of Geophysics and Engineering, ISSN: 17422132, eISSN: 17422140, Pages: 162-175, Published: April 2012 Oxford University Press (OUP)
Unconventional reservoirs such as fractured basalts, shale gas and tight sand are currently playing an important role in producing a significant amount of hydrocarbon. The Deccan Trap basaltic rocks form the basement of the Cambay Basin, India, and hold commercially producible hydrocarbon. In this study two wells drilled through fractured basalts are chosen for evaluating the lithology, porosity and oil saturation of the reservoir sections. Well logs, such as gamma ray, high resolution resistivity, litho density, compensated neutron and elemental capture spectroscopy, have been used in cross-plotting techniques for lithology and mineral identification. Formation micro imagery log data have been analysed to quantify the fractures and porosity in the fractured reservoirs for a well in the south Ahmedabad block of the Cambay Basin. The results of the analysis of two wells are presented and discussed and they are found to be in good agreement with geological and production data.
International Petroleum Technology Conference 2011, IPTC 2011, Published: 2011
Mining Engineering, ISSN: 00265187, Pages: 48-52, Published: January 2000