The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Shuichang Zhang - One of the best experts on this subject based on the ideXlab platform.
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unique chemical and isotopic characteristics and origins of natural gases in the paleozoic marine formations in the sichuan basin sw china isotope fractionation of deep and high mature Carbonate Reservoir gases
Marine and Petroleum Geology, 2018Co-Authors: Shuichang Zhang, Keyu Liu, Yongchun TangAbstract:Abstract Large quantities of natural gases have recently been discovered in the marine Carbonate formations in the Sichuan Basin, southern China. The origins and isotopic compositions of the gases are poorly understood and highly controversial. We examined the chemical and isotopic compositions of the Carbonate Reservoir gases in marine formations from the Sinian to Lower Triassic as well as shale gas from the Silurian and Cambrian Formation in the Sichuan Basin. It is found that the carbon isotopes of the Carbonate Reservoir gases had been evolved through three stages corresponding to pre-rollover, rollover and post-rollover in the plot of δ13C2 versus wetness, which is consistent with that found in shale gas by Tilley and Muehlenbachs (2013). The unique carbon isotopic compositions indicate that both kerogen and oil-cracking gas have contributed to the accumulation of the Carbonate Reservoir gases in the Sichuan Basin. A mixing of two thermogenic gases with different maturities can cause the δ13C reversal between methane and ethane, which is commonly observed in the Carbonate Reservoir gases in the Carboniferous, Permian and Triassic formations, and the shale gas in the Silurian and Cambrian formations in the Sichuan Basin. We established two mixing models for quantitatively determining the contribution of each type gas for the natural gases in different formations. Kinetic extrapolation based on thermal history of the Anyue gas field demonstrates that ethane cracking indeed occurred in the deep Reservoir formations, which may explain the disappearance of the 13C reversal for methane and ethane in the Carbonate Reservoir gases in the post-rollover zone. It is proposed that organic-inorganic interactions may be responsible for the presence of D isotope rollover for methane in Carbonate Reservoir gases with ultra-high maturity. The organic-inorganic interactions include thermal reactions between water and residual organic matters or carbons and hydrogen isotope exchange between water and methane, and their mechanism needs further investigations in future.
Waleed Al Ameri - One of the best experts on this subject based on the ideXlab platform.
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tuning foam parameters for mobility control using co2 foam field application to maximize oil recovery from a high temperature high salinity layered Carbonate Reservoir
Energy & Fuels, 2017Co-Authors: Ali Al Sumaiti, Abdul Ravoof Shaik, Eric Sonny Mathew, Waleed Al AmeriAbstract:This paper investigates the reduction in gas mobility during the EOR (enhanced oil recovery) process of gas injection due to the presence of foam, thereby increasing sweep efficiency. The presented work is focused on developing a systematic approach to tune the CO2 foam parameters based on two separate core flooding experiments, the former conducted at variable foam qualities while the latter at a fixed foam quality. The paper discusses the experimental data required for the modeling of mobility control using CO2-foam for a high temperature, high salinity layered Carbonate Reservoir. An empirical foam model is used for parametric matching of laboratory data, and foam parameters are calculated and tuned. The key objective of the model is not only to match the measured apparent foam viscosity for varying foam qualities but also be able to capture the pressure drop measured for various experimental runs. The tuned foam model can be applied to field scale and design the injection strategy to maximize the oil ...
M M Alfahmi - One of the best experts on this subject based on the ideXlab platform.
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comparison of Carbonate Reservoir fractures from core and modern electrical borehole images
Marine and Petroleum Geology, 2019Co-Authors: M M Alfahmi, Joe CartwrightAbstract:Abstract Several methods exist for collecting data about opening-mode fractures (hereinafter fractures) in subsurface Reservoir rocks. The datasets, with the exception of core data, are indirect and subject to limited resolutions. This paper includes new results on the detection of fractures in Carbonate Reservoirs by modern electrical borehole imagers. Barren fractures and calcite-filled fractures (calcite veins) were described and compared from whole core and borehole images. These datasets were obtained from directional drilling into the Arab petroleum Reservoirs in a low-relief dome structure in Eastern Arabia. The comparison of fracture abundance resulted in a significant mismatch, because many Reservoir fractures in the core could not be detected from corresponding borehole images. Most calcite veins were undetected because of their small widths, below 2 mm. Exceptions include a few calcite veins of 0.5 mm that were detected because of the strong contrast between resistive veins and conductive host rock beds. The barren fractures that are aligned sub-parallel to the maximum horizontal principal stress (SHmax) were detected more abundantly than other non-aligned barren fractures. The present-day SHmax is roughly trending between 60° and 100° azimuth in Eastern Arabia. The aligned fractures have larger apertures in the borehole images than the non-aligned fractures. The apertures diminish in size as the fractures gradually deviate in orientation from the SHmax. Most of the non-aligned barren fractures were undetected, except the fractures with rough and mismatching walls. This indicates that the walls of the non-aligned fractures are mechanically closed by the normal SHmax, and that the remaining apertures were dependent on the availability of roughness mismatches between the closed fracture walls. Electrical borehole images are biased in measuring fracture abundance, but indispensable to detect and measure the orientations and apertures of fractures, especially the large (i.e., more conductive) fractures in Reservoir rocks.
J Tritlla - One of the best experts on this subject based on the ideXlab platform.
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petroleum accumulation and leakage in a deeply buried Carbonate Reservoir nispero field mexico
Marine and Petroleum Geology, 2010Co-Authors: Julien Bourdet, Jacques Pironon, Gilles Levresse, J TritllaAbstract:Abstract The filling history of the Nispero deeply buried Lower Cretaceous Carbonate Reservoir (below 4000 m) from the south part of Gulf of Mexico was studied using a combination of data from petrography, stable isotopes and fluid inclusions and compared with a one-dimensional burial model to derive timing. A combination of techniques such as microthermometry, confocal laser scanning microscopy (CLSM) and Raman microspectroscopy have been used to characterize the different fluid inclusion assemblages and discriminate between the reequilibrated and the preserved fluid inclusions. The Nispero Reservoir is composed of a fractured finely crystalline replacement dolostone. A first generation of fractures is filled by a non-planar dolomite cement, and a second generation by a planar-E dolomite cement and a blocky sparite. The Reservoir is lastly stylolitised. Dolomite has δ13C values between 0.9 and 4.0‰ (PDB) and δ18O values between −4.5 and −10.8‰ (PDB). Calcite has δ13C values between 3.8 and 4.4‰ (PDB) and δ18O values between −4.9 and −5.5‰ (PDB). These values suggest that the calcite represents a change in water composition and that dolomite and calcite cements do not precipitate from petroleum-derived fluids. However, geological fluids are trapped as aqueous and oil inclusions in the calcite cements. Three petroleum-aqueous inclusion assemblages were identified: pseudo-primary brown oil paired with brine inclusions and pseudo-primary yellow oil paired with low salinity water inclusions distributed in local concentrations; and secondary colourless oil paired with low salinity aqueous inclusions distributed in healed microfractures. The burial model, calibrated with bottom-hole temperatures, has been calculated using PetroMod® 1D to generate the rock PT history under hydrostatic and lithostatic regimes. Reconstructed temperatures of initial trapping of fluid inclusion and calculated temperatures from δ18O measured in dolomite and calcite cements are in good agreement. Data suggests that the Reservoir was being filled at 97 °C–315 bar by heavy black oils accompanied by high salinity water during the Miocene period (11.6 m.y.). The maximum estimated pressure of 700 bar at 130 °C is reconstructed by petroleum inclusions trapping black oil and associated low salinity aqueous inclusions. These PT conditions were reached during the Pliocene (3–2m.y.). Present day Reservoir conditions of 145 °C and 500 bar are recorded by reequilibration of most of the fluid inclusions of the two assemblages and correspond to hydrostatic pressure. The drop of pressure from 700 bar to 500 bar may be an explanation for the late stylolitisation.
Yongchun Tang - One of the best experts on this subject based on the ideXlab platform.
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unique chemical and isotopic characteristics and origins of natural gases in the paleozoic marine formations in the sichuan basin sw china isotope fractionation of deep and high mature Carbonate Reservoir gases
Marine and Petroleum Geology, 2018Co-Authors: Shuichang Zhang, Keyu Liu, Yongchun TangAbstract:Abstract Large quantities of natural gases have recently been discovered in the marine Carbonate formations in the Sichuan Basin, southern China. The origins and isotopic compositions of the gases are poorly understood and highly controversial. We examined the chemical and isotopic compositions of the Carbonate Reservoir gases in marine formations from the Sinian to Lower Triassic as well as shale gas from the Silurian and Cambrian Formation in the Sichuan Basin. It is found that the carbon isotopes of the Carbonate Reservoir gases had been evolved through three stages corresponding to pre-rollover, rollover and post-rollover in the plot of δ13C2 versus wetness, which is consistent with that found in shale gas by Tilley and Muehlenbachs (2013). The unique carbon isotopic compositions indicate that both kerogen and oil-cracking gas have contributed to the accumulation of the Carbonate Reservoir gases in the Sichuan Basin. A mixing of two thermogenic gases with different maturities can cause the δ13C reversal between methane and ethane, which is commonly observed in the Carbonate Reservoir gases in the Carboniferous, Permian and Triassic formations, and the shale gas in the Silurian and Cambrian formations in the Sichuan Basin. We established two mixing models for quantitatively determining the contribution of each type gas for the natural gases in different formations. Kinetic extrapolation based on thermal history of the Anyue gas field demonstrates that ethane cracking indeed occurred in the deep Reservoir formations, which may explain the disappearance of the 13C reversal for methane and ethane in the Carbonate Reservoir gases in the post-rollover zone. It is proposed that organic-inorganic interactions may be responsible for the presence of D isotope rollover for methane in Carbonate Reservoir gases with ultra-high maturity. The organic-inorganic interactions include thermal reactions between water and residual organic matters or carbons and hydrogen isotope exchange between water and methane, and their mechanism needs further investigations in future.