The Sawan gas field(SGF)is located in Pakistan's central Indus Basin in the Province of Sindh,Pakistan.Tectonically,it is part of the southeastern Jacobabad high;and geographically,it is part of the Thar Desert in...The Sawan gas field(SGF)is located in Pakistan's central Indus Basin in the Province of Sindh,Pakistan.Tectonically,it is part of the southeastern Jacobabad high;and geographically,it is part of the Thar Desert in the Khairpur district.In the present study,three wells,Sawan 01,Sawan 02 and Sawan 08,were analyzed for reservoir properties of the Lower Goru C sand interval,which has been drilled in the central part of the field.Petrophysical parameters such as effective porosity,the volume of shale,formation water resistivity,and water saturation of the studied basin were calculated.In terms of shale volume,Sawan 01 has 30%–35%of non-clean(shale)lithology,which is the highest of the three wells.The effective porosity of the three wells ranges from 12%–16%,while the average water saturation in the interval of C sand in these wells stands around 50%–60%.But there are zones with relatively lower water saturation values of approximately 30%–50%.These zones are considered better pay zones than the rest of the intervals.A very interesting phenomenon that may be termed the"Gas effect"is visible on cross plots,representing the neutron-density cross over on the E-Logs layout and representing the presence of lighter hydrocarbons in this reservoir zone.展开更多
This study aimed at characterizing and classifying crude oils with the view of inferring source rock characteristics from the chemistry of oils and thus infer-ring the hydrocarbon resource potential.The use of Gas Chr...This study aimed at characterizing and classifying crude oils with the view of inferring source rock characteristics from the chemistry of oils and thus infer-ring the hydrocarbon resource potential.The use of Gas Chromatographic-Flame Ionization Detector traces(GC-FID)in indicating Kibiro,Nzizi2 Mur-ram Pit,Runga,and Sonso is heavily biodegraded oil seep samples and Mputa-1,Mputa-3,Mputa-4,Waraga-1,and Nzizi-2 oil samples are non-degraded oils.From the Ternary diagram,Mputa-1,Mputa-3,Mputa-4,Waraga-1,and Nzizi-2 oils belong to Paraffinic oils while Kibiro and Nzizi-2 Murram Pit oil seeps are classified as Paraffinic-napthenic oils,and Runga and Sonso oil seeps be long to Napthenic oils.The plots of Moretane/Hopane vs Ts/Tm,20S/(20S+20R)for C_(27)sterane vs 22S/(22S+22R)for C31-homohopane,and saturates,aromatics and NSO+Asph and ratios ofαββ/(αββ+ααα)for C_(29)-sterane and Ts/(Ts+Tm)show that the studied oil seep and oil samples originated from mature source rock which has tendency to yield significant amount of hydro carbon.A plot of DBT/Phen vs NH/Hop,diasteranes/Steranes vs dH/29Ts and ratios of CPI,DBT/Phen,Pr/Ph suggests that oil and seep samples are derived from shale source rock which yields significant quantity of hydrocarbons.展开更多
文摘The Sawan gas field(SGF)is located in Pakistan's central Indus Basin in the Province of Sindh,Pakistan.Tectonically,it is part of the southeastern Jacobabad high;and geographically,it is part of the Thar Desert in the Khairpur district.In the present study,three wells,Sawan 01,Sawan 02 and Sawan 08,were analyzed for reservoir properties of the Lower Goru C sand interval,which has been drilled in the central part of the field.Petrophysical parameters such as effective porosity,the volume of shale,formation water resistivity,and water saturation of the studied basin were calculated.In terms of shale volume,Sawan 01 has 30%–35%of non-clean(shale)lithology,which is the highest of the three wells.The effective porosity of the three wells ranges from 12%–16%,while the average water saturation in the interval of C sand in these wells stands around 50%–60%.But there are zones with relatively lower water saturation values of approximately 30%–50%.These zones are considered better pay zones than the rest of the intervals.A very interesting phenomenon that may be termed the"Gas effect"is visible on cross plots,representing the neutron-density cross over on the E-Logs layout and representing the presence of lighter hydrocarbons in this reservoir zone.
文摘This study aimed at characterizing and classifying crude oils with the view of inferring source rock characteristics from the chemistry of oils and thus infer-ring the hydrocarbon resource potential.The use of Gas Chromatographic-Flame Ionization Detector traces(GC-FID)in indicating Kibiro,Nzizi2 Mur-ram Pit,Runga,and Sonso is heavily biodegraded oil seep samples and Mputa-1,Mputa-3,Mputa-4,Waraga-1,and Nzizi-2 oil samples are non-degraded oils.From the Ternary diagram,Mputa-1,Mputa-3,Mputa-4,Waraga-1,and Nzizi-2 oils belong to Paraffinic oils while Kibiro and Nzizi-2 Murram Pit oil seeps are classified as Paraffinic-napthenic oils,and Runga and Sonso oil seeps be long to Napthenic oils.The plots of Moretane/Hopane vs Ts/Tm,20S/(20S+20R)for C_(27)sterane vs 22S/(22S+22R)for C31-homohopane,and saturates,aromatics and NSO+Asph and ratios ofαββ/(αββ+ααα)for C_(29)-sterane and Ts/(Ts+Tm)show that the studied oil seep and oil samples originated from mature source rock which has tendency to yield significant amount of hydro carbon.A plot of DBT/Phen vs NH/Hop,diasteranes/Steranes vs dH/29Ts and ratios of CPI,DBT/Phen,Pr/Ph suggests that oil and seep samples are derived from shale source rock which yields significant quantity of hydrocarbons.
