The microfacies, depositional environment, and reservoir potential of the Sakesar Formation have ... more The microfacies, depositional environment, and reservoir potential of the Sakesar Formation have been evaluated using detailed petrographic and petrophysical techniques at the surface (Pail village exposed section) and subsurface (Amir Pur oilfield well). Ten samples were collected from a stratigraphic exposed sections of Sakesar Formation at Pail Village in Potwar Basin, Pakistan. Microscopic analysis of the samples revealed two microfacies: Numulitic wackestone and Millioloidal wackestone. The texture of the wackestone in the Sakesar Limestone at the studied section indicates that it was formed in a shallow area of the middle shelf. This is supported by the presence of certain types of fossils. The limestone is mostly gray, hard, and contains fossils and chert nodules in the upper portion, with some interspersed marl and shale in the lower section Wireline log data from the Amir Pur well were used to evaluate the reservoir potential, with results showing 5.3% sonic porosity and 3....
Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences
By using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements, the hydrocarb... more By using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements, the hydrocarbon source rock potential of Chichali and Samana Suk formations found in the subsurface of Panjpir oilfield in Punjab platform located in the eastern part of the middle Indus Basin was investigated. Twenty two core samples were collected from producing well. The analysed samples of Chichali formation contains TOC ranging between 0.99-4.61 wt.% having average TOC of 1.51 wt.% and the S2 values of Rock-Eval show the poor to fair generative potential with values ranging from 0.99-3.08 mg HC/g rock. The samples have low hydrogen index values ranging from 21-302 mg HC/g TOC and also most of the samples have low T_(max ) values ranging from 422-432 °C and have OI values ranging from 15-82 mg CO2/g TOC. Samana Suk formation samples have TOC ranging between 0.28-1.38 wt.% having average TOC of 0.84 wt.%. S2 values of Rock-Eval shows poor generative potential with values ranging from 0.05-2.99 mg ...
Cretaceous and Jurassic deposits in the sub-surface of Ahmedpur East Oilfield, Punjab Platform, P... more Cretaceous and Jurassic deposits in the sub-surface of Ahmedpur East Oilfield, Punjab Platform, Pakistan, have been geochemically analysed. Source rock potential of three formations namely Mughal Kot and Goru (Cretaceous) and Samana Suk (Jurassic) located in Middle Indus Basin have been investigated. The formations were investigated using total organic carbon and Rock-Eval pyrolysis analysis measurements. Analysis were performed on fourteen samples from wells, having TOC 0.57–1.65 wt.%, the S2 values of the sample shows poor to fair generative potential and lies between 0.25–2.59 mg HC/g rock, HI values are generally low 37–150 mg HC/g TOC and Tmax values ranges from 417–453 °C. The analysis shows Mughal Kot and Samana Suk formations samples have entered maturity window zone, however Goru Formation samples lies in immature zones, shown by hydrogen index vs Tmax plot. The samples from Mughal Kot and Goru formations have kerogen type III with poor generative potential, however Samana Suk Formation have fair generative potential having kerogen type III indicated by S2 vs TOC plot, hence from the results some minor gas could be expected to have been generated by Samana Suk Formation. Targeting these formations as a source rock to expel hydrocarbons involves high risk and exploration of such reserves may not be beneficial in terms of economic value.
Journal of Petroleum Science and Engineering, 2020
The current study aimed to explore the gas-generating potential and oil-togas conversion in the M... more The current study aimed to explore the gas-generating potential and oil-togas conversion in the Madbi oil-source rock system based on data from deep well within the Say'un-Masila Basin using both geochemical and petrological methods as well as basin models. Biomarker results for the bitumen from analyzed shale samples indicate mixed organic matter, with mainly phytoplankton, bacteria, and some terrigenous land plants, deposited under relatively anoxic marine environmental conditions. The terrigenous organic matter, and rich in lipids from phytoplankton and bacteria, suggests Types II and II/III as the original organic matter during deposition. Such findings are not consistent with the significant amounts of vitrinite and inertinite that found under microscope and the low current hydrogen index (HI) values of 43-282 (Types III/IV and III/II kerogen) of the analyzed shale samples. The chemical and optical maturity indicators show that the Madbi shales throughout the studied well section are at different thermal maturity stages, consistent with late-mature stage of the oil window to gasgeneration window. Therefore, this high thermal maturation is the critical factor that significantly modifies the original organic matter. Based on the basin models of the single well studied (Ghayl Bin Yumain-01), the initial conversion of kerogen to oil, occurring between the Late Cretaceous and Late Eocene (75-38 Ma), corresponding to peak-oil window (0.70-1.00 Easy %R o). Furthermore, the oil was expelled during the Late Eocene to Early Oligocene; hence, the late-mature stage of the oil window (1.00-1.30 Easy %R o) commenced during this time, with transformation ratios (TR) of 50-70%. Subsequently, the cracking of the retained oil into gas has occurred from the Early Oligocene through the present and is attributed to the high thermal maturation of the gas window (>1.30 Easy % R o), with maximum TRs of 70-97%.
The Ranikot sandstone Formation was investigated using TOC and Rock-Eval pyrolysis measurements. ... more The Ranikot sandstone Formation was investigated using TOC and Rock-Eval pyrolysis measurements. Ranikot Formation encountered in Bijnot well, Fort Abbas has been evaluated, which lies in Bahawalpur, middle Indus basin, particularly in Punjab platform. Analysis has been performed on sandstones, twenty well cutting samples of Ranikot Formation has been evaluated. Formation is predominantly sandstone with interbeds of shale. The analysed samples contains TOC ranging from 0.76-3.1 wt.%, The S2 values of Rock-Eval shows poor potential with values ranging from 0.46-1.05 mg HC/g rock. The samples have low hydrogen index values ranging from 21-113 mg HC/g TOC. Kerogen is predominantly Type III land derived organic matter. The analysed samples have T max ranging from 413-509 °C. The upper part of formation from 490-560m depth generally exhibits good to very good TOC content and is in the transition between immature and mature zone (Tmax 430-431 °C). The genetic potential in the entire rock unit is poor < 2.0 mg HC/g rock. On the basis of analysis performed the studied samples have shown that the formation has poor potential.
Bituminous lime mudstone from the Late Tithonian-Early Barremian Naifa Formation was collected fr... more Bituminous lime mudstone from the Late Tithonian-Early Barremian Naifa Formation was collected from five wells in the Shabwah depression of the southeastern Sabatayn Basin for basic organic geochemical analyses. The collected samples' nannofossil contents were also studied. The current study preliminarily evaluated the nature of the organic matter regarding the richness and type of organic facies and their relation to oil generation potential. Most of the lime mudstone samples are organically rich and include favorable source rocks, as indicated by the high TOC content of up to 1 wt%. The presence of the warm-water index nannofossil taxa Watznaueria barnesae suggests warm climate conditions, thereby contributing to high bioproductivity that consequently enhanced organic richness. The samples are also hydrogen rich, with HI values between 302 and 740 mg HC/g TOC, resulting in two dominant organic facies of kerogen Types I and II, and are consistent with high bioproductivity of phytoplankton algae in warm-water conditions during deposition. Both geochemical maturity values T max and PI indicate that the bituminous lime mudstones are at different thermal maturity levels and range from immature to early mature stages of the oil generation window. This implies that the bituminous lime mudstones were not buried to a sufficient depth for commercial oil generation. Therefore, further exploration efforts in deeper parts of the Shabwah depression, particularly in the area around well Misah-01, are recommended.
Bulletin of the Geological Society of Malaysia, 2016
The Balkassar Oilfield is located in the eastern Potwar sub-basin, and lies on the Soan Syncline ... more The Balkassar Oilfield is located in the eastern Potwar sub-basin, and lies on the Soan Syncline southern flank of the Himalayan collisional regime. In this study, petrophysical properties of reservoir rock of the Chorgali Formation of Eocene age encountered in well 7 of the Balkassar Oilfield were evaluated for reservoir rock potentiality. A set of wireline logs containing neutron, density, gamma ray, spontaneous potential and resistivity logs of well 7 from Balkassar Oilfield were interpreted carefully to estimate porosity, water saturation and hydrocarbon saturation. The method used for this petrophysical analysis is spontaneous potential logs in calculating water resistivity followed by Archie's equation to convert water resistivity to water saturation. Based on the petrophysical analysis performed on the Balkassar well 7, the results show that about 21.1% average porosity, 33.5% water saturation and 66.5% hydrocarbons saturation were obtained for the Chorgali Formation. Thus, this indicates that Chorgali Formation has an average to good reservoir potential.
Hydrocarbon source rock potential of three formations in Panjpir oilfield in Punjab Platform in t... more Hydrocarbon source rock potential of three formations in Panjpir oilfield in Punjab Platform in the eastern part of the Middle Indus Basin, namely Ranikot (Paleocene), Samanasuk (Jurassic), and Shinwari (Jurassic) was investigated by using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements. Nine samples were obtained from producing well. The analyzed samples contain TOC ranging between 0.98 and 2.45 wt.%. S2 values of Rock-Eval show poor potential with values ranging from 0.02 to 0.27 mg HC/g rock. The samples have low hydrogen index values ranging from 3 to 27 mg HC/g TOC and also having low T max values ranging from 427 to 431°C. On the basis of analysis performed, only three studied samples have early maturity, two from Ranikot and one from Samana Suk formation, whereas rest of the samples are in immature zones as indicated by HI vs T max plot; no samples from Shinwari Formation lie in maturity window. All of the samples have kerogen Type III and have poor generation potential. Hence, from the result, some minor gas could be expected to have been generated in the study area.
The Balkassar oil field is situated in the eastern Potwar subbasin, lies on the southern flank of... more The Balkassar oil field is situated in the eastern Potwar subbasin, lies on the southern flank of Soan syncline in Himalayan collisional regime. The area represents Indo-Pak and Eurasian blocks of Precambrian to recent time. Thrusting and folding of Himalayan, Indo-Pak plate movement and Salt Range uplift form the structural trap in Balkassar sub-surface (Balkassar anticline). On the basis of information from eleven seismic 2D lines and wells data six reflectors well data, four faults were identified and marked. The structural trend is northeast southwest. Interpretation of seismic 2D data reveals that the study area has undergone intense deformation as a consequence of development of thrusts and backthrusts. The Balkassar anticline is bounded by two thrust faults one from southeast and the other from northwest. Time and depth contour models shows that anticline limbs at northwestern side are steep as compared to southeastern limbs. Seismic interpretation indicates the presence of well-developed anticline bounded by three faults in the cover sequence and one fault in basement and thus the structure may act as a trap for hydrocarbons. The petrophysical analysis of Balkassar-OXY-1 well shows about 83.1% hydrocarbons saturation in the reservoir rocks, hence this study suggest that Balkassar Oilfield has potential to produce hydrocarbons.
The microfacies, depositional environment, and reservoir potential of the Sakesar Formation have ... more The microfacies, depositional environment, and reservoir potential of the Sakesar Formation have been evaluated using detailed petrographic and petrophysical techniques at the surface (Pail village exposed section) and subsurface (Amir Pur oilfield well). Ten samples were collected from a stratigraphic exposed sections of Sakesar Formation at Pail Village in Potwar Basin, Pakistan. Microscopic analysis of the samples revealed two microfacies: Numulitic wackestone and Millioloidal wackestone. The texture of the wackestone in the Sakesar Limestone at the studied section indicates that it was formed in a shallow area of the middle shelf. This is supported by the presence of certain types of fossils. The limestone is mostly gray, hard, and contains fossils and chert nodules in the upper portion, with some interspersed marl and shale in the lower section Wireline log data from the Amir Pur well were used to evaluate the reservoir potential, with results showing 5.3% sonic porosity and 3....
Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences
By using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements, the hydrocarb... more By using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements, the hydrocarbon source rock potential of Chichali and Samana Suk formations found in the subsurface of Panjpir oilfield in Punjab platform located in the eastern part of the middle Indus Basin was investigated. Twenty two core samples were collected from producing well. The analysed samples of Chichali formation contains TOC ranging between 0.99-4.61 wt.% having average TOC of 1.51 wt.% and the S2 values of Rock-Eval show the poor to fair generative potential with values ranging from 0.99-3.08 mg HC/g rock. The samples have low hydrogen index values ranging from 21-302 mg HC/g TOC and also most of the samples have low T_(max ) values ranging from 422-432 °C and have OI values ranging from 15-82 mg CO2/g TOC. Samana Suk formation samples have TOC ranging between 0.28-1.38 wt.% having average TOC of 0.84 wt.%. S2 values of Rock-Eval shows poor generative potential with values ranging from 0.05-2.99 mg ...
Cretaceous and Jurassic deposits in the sub-surface of Ahmedpur East Oilfield, Punjab Platform, P... more Cretaceous and Jurassic deposits in the sub-surface of Ahmedpur East Oilfield, Punjab Platform, Pakistan, have been geochemically analysed. Source rock potential of three formations namely Mughal Kot and Goru (Cretaceous) and Samana Suk (Jurassic) located in Middle Indus Basin have been investigated. The formations were investigated using total organic carbon and Rock-Eval pyrolysis analysis measurements. Analysis were performed on fourteen samples from wells, having TOC 0.57–1.65 wt.%, the S2 values of the sample shows poor to fair generative potential and lies between 0.25–2.59 mg HC/g rock, HI values are generally low 37–150 mg HC/g TOC and Tmax values ranges from 417–453 °C. The analysis shows Mughal Kot and Samana Suk formations samples have entered maturity window zone, however Goru Formation samples lies in immature zones, shown by hydrogen index vs Tmax plot. The samples from Mughal Kot and Goru formations have kerogen type III with poor generative potential, however Samana Suk Formation have fair generative potential having kerogen type III indicated by S2 vs TOC plot, hence from the results some minor gas could be expected to have been generated by Samana Suk Formation. Targeting these formations as a source rock to expel hydrocarbons involves high risk and exploration of such reserves may not be beneficial in terms of economic value.
Journal of Petroleum Science and Engineering, 2020
The current study aimed to explore the gas-generating potential and oil-togas conversion in the M... more The current study aimed to explore the gas-generating potential and oil-togas conversion in the Madbi oil-source rock system based on data from deep well within the Say'un-Masila Basin using both geochemical and petrological methods as well as basin models. Biomarker results for the bitumen from analyzed shale samples indicate mixed organic matter, with mainly phytoplankton, bacteria, and some terrigenous land plants, deposited under relatively anoxic marine environmental conditions. The terrigenous organic matter, and rich in lipids from phytoplankton and bacteria, suggests Types II and II/III as the original organic matter during deposition. Such findings are not consistent with the significant amounts of vitrinite and inertinite that found under microscope and the low current hydrogen index (HI) values of 43-282 (Types III/IV and III/II kerogen) of the analyzed shale samples. The chemical and optical maturity indicators show that the Madbi shales throughout the studied well section are at different thermal maturity stages, consistent with late-mature stage of the oil window to gasgeneration window. Therefore, this high thermal maturation is the critical factor that significantly modifies the original organic matter. Based on the basin models of the single well studied (Ghayl Bin Yumain-01), the initial conversion of kerogen to oil, occurring between the Late Cretaceous and Late Eocene (75-38 Ma), corresponding to peak-oil window (0.70-1.00 Easy %R o). Furthermore, the oil was expelled during the Late Eocene to Early Oligocene; hence, the late-mature stage of the oil window (1.00-1.30 Easy %R o) commenced during this time, with transformation ratios (TR) of 50-70%. Subsequently, the cracking of the retained oil into gas has occurred from the Early Oligocene through the present and is attributed to the high thermal maturation of the gas window (>1.30 Easy % R o), with maximum TRs of 70-97%.
The Ranikot sandstone Formation was investigated using TOC and Rock-Eval pyrolysis measurements. ... more The Ranikot sandstone Formation was investigated using TOC and Rock-Eval pyrolysis measurements. Ranikot Formation encountered in Bijnot well, Fort Abbas has been evaluated, which lies in Bahawalpur, middle Indus basin, particularly in Punjab platform. Analysis has been performed on sandstones, twenty well cutting samples of Ranikot Formation has been evaluated. Formation is predominantly sandstone with interbeds of shale. The analysed samples contains TOC ranging from 0.76-3.1 wt.%, The S2 values of Rock-Eval shows poor potential with values ranging from 0.46-1.05 mg HC/g rock. The samples have low hydrogen index values ranging from 21-113 mg HC/g TOC. Kerogen is predominantly Type III land derived organic matter. The analysed samples have T max ranging from 413-509 °C. The upper part of formation from 490-560m depth generally exhibits good to very good TOC content and is in the transition between immature and mature zone (Tmax 430-431 °C). The genetic potential in the entire rock unit is poor < 2.0 mg HC/g rock. On the basis of analysis performed the studied samples have shown that the formation has poor potential.
Bituminous lime mudstone from the Late Tithonian-Early Barremian Naifa Formation was collected fr... more Bituminous lime mudstone from the Late Tithonian-Early Barremian Naifa Formation was collected from five wells in the Shabwah depression of the southeastern Sabatayn Basin for basic organic geochemical analyses. The collected samples' nannofossil contents were also studied. The current study preliminarily evaluated the nature of the organic matter regarding the richness and type of organic facies and their relation to oil generation potential. Most of the lime mudstone samples are organically rich and include favorable source rocks, as indicated by the high TOC content of up to 1 wt%. The presence of the warm-water index nannofossil taxa Watznaueria barnesae suggests warm climate conditions, thereby contributing to high bioproductivity that consequently enhanced organic richness. The samples are also hydrogen rich, with HI values between 302 and 740 mg HC/g TOC, resulting in two dominant organic facies of kerogen Types I and II, and are consistent with high bioproductivity of phytoplankton algae in warm-water conditions during deposition. Both geochemical maturity values T max and PI indicate that the bituminous lime mudstones are at different thermal maturity levels and range from immature to early mature stages of the oil generation window. This implies that the bituminous lime mudstones were not buried to a sufficient depth for commercial oil generation. Therefore, further exploration efforts in deeper parts of the Shabwah depression, particularly in the area around well Misah-01, are recommended.
Bulletin of the Geological Society of Malaysia, 2016
The Balkassar Oilfield is located in the eastern Potwar sub-basin, and lies on the Soan Syncline ... more The Balkassar Oilfield is located in the eastern Potwar sub-basin, and lies on the Soan Syncline southern flank of the Himalayan collisional regime. In this study, petrophysical properties of reservoir rock of the Chorgali Formation of Eocene age encountered in well 7 of the Balkassar Oilfield were evaluated for reservoir rock potentiality. A set of wireline logs containing neutron, density, gamma ray, spontaneous potential and resistivity logs of well 7 from Balkassar Oilfield were interpreted carefully to estimate porosity, water saturation and hydrocarbon saturation. The method used for this petrophysical analysis is spontaneous potential logs in calculating water resistivity followed by Archie's equation to convert water resistivity to water saturation. Based on the petrophysical analysis performed on the Balkassar well 7, the results show that about 21.1% average porosity, 33.5% water saturation and 66.5% hydrocarbons saturation were obtained for the Chorgali Formation. Thus, this indicates that Chorgali Formation has an average to good reservoir potential.
Hydrocarbon source rock potential of three formations in Panjpir oilfield in Punjab Platform in t... more Hydrocarbon source rock potential of three formations in Panjpir oilfield in Punjab Platform in the eastern part of the Middle Indus Basin, namely Ranikot (Paleocene), Samanasuk (Jurassic), and Shinwari (Jurassic) was investigated by using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements. Nine samples were obtained from producing well. The analyzed samples contain TOC ranging between 0.98 and 2.45 wt.%. S2 values of Rock-Eval show poor potential with values ranging from 0.02 to 0.27 mg HC/g rock. The samples have low hydrogen index values ranging from 3 to 27 mg HC/g TOC and also having low T max values ranging from 427 to 431°C. On the basis of analysis performed, only three studied samples have early maturity, two from Ranikot and one from Samana Suk formation, whereas rest of the samples are in immature zones as indicated by HI vs T max plot; no samples from Shinwari Formation lie in maturity window. All of the samples have kerogen Type III and have poor generation potential. Hence, from the result, some minor gas could be expected to have been generated in the study area.
The Balkassar oil field is situated in the eastern Potwar subbasin, lies on the southern flank of... more The Balkassar oil field is situated in the eastern Potwar subbasin, lies on the southern flank of Soan syncline in Himalayan collisional regime. The area represents Indo-Pak and Eurasian blocks of Precambrian to recent time. Thrusting and folding of Himalayan, Indo-Pak plate movement and Salt Range uplift form the structural trap in Balkassar sub-surface (Balkassar anticline). On the basis of information from eleven seismic 2D lines and wells data six reflectors well data, four faults were identified and marked. The structural trend is northeast southwest. Interpretation of seismic 2D data reveals that the study area has undergone intense deformation as a consequence of development of thrusts and backthrusts. The Balkassar anticline is bounded by two thrust faults one from southeast and the other from northwest. Time and depth contour models shows that anticline limbs at northwestern side are steep as compared to southeastern limbs. Seismic interpretation indicates the presence of well-developed anticline bounded by three faults in the cover sequence and one fault in basement and thus the structure may act as a trap for hydrocarbons. The petrophysical analysis of Balkassar-OXY-1 well shows about 83.1% hydrocarbons saturation in the reservoir rocks, hence this study suggest that Balkassar Oilfield has potential to produce hydrocarbons.
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