The Taoudeni Basin is a typical and steady intracratonic basin in Mauritania, northwest Africa. There are six sets of potential source rocks and five regional unconformable surfaces of the Infracambrian and Paleozoic ...The Taoudeni Basin is a typical and steady intracratonic basin in Mauritania, northwest Africa. There are six sets of potential source rocks and five regional unconformable surfaces of the Infracambrian and Paleozoic developed in the basin. We used seismic stratigraphic correlation to recover the denudation thickness of formations at a particular well location. Studies of the hydrocarbon generation history of the basin illustrate that hydrocarbon migration and accumulation occurred in the end of the Carboniferous, and after that, the whole basin suffered denudation for a long period of time. Because there is no thick Mesozoic overburden in the basin, the Silurian source rocks could not generate hydrocarbon in the Mesozoic era for the second time. Consequently, the prospects for successful hydrocarbon exploration in the basin are not good.展开更多
Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and t...Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil ＆ gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks. Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.展开更多
文摘The Taoudeni Basin is a typical and steady intracratonic basin in Mauritania, northwest Africa. There are six sets of potential source rocks and five regional unconformable surfaces of the Infracambrian and Paleozoic developed in the basin. We used seismic stratigraphic correlation to recover the denudation thickness of formations at a particular well location. Studies of the hydrocarbon generation history of the basin illustrate that hydrocarbon migration and accumulation occurred in the end of the Carboniferous, and after that, the whole basin suffered denudation for a long period of time. Because there is no thick Mesozoic overburden in the basin, the Silurian source rocks could not generate hydrocarbon in the Mesozoic era for the second time. Consequently, the prospects for successful hydrocarbon exploration in the basin are not good.
基金Supported by National Natural Science Fund 40472078 and the Project of "973 plan" G1999043310
文摘Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil ＆ gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks. Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.
