The characteristics and formation mechanism of clastic reservoirs have a significant impact on petroleum accumulation in the deep-seated strata of sedimentary basins.Newly drill data indicate that the tight reservoirs...The characteristics and formation mechanism of clastic reservoirs have a significant impact on petroleum accumulation in the deep-seated strata of sedimentary basins.Newly drill data indicate that the tight reservoirs in the lower slop of Fukang Sag in the Junggar Basin produce a lot of oil despite being buried extremely deep and with low porosity.By using lithological and geochemical studies,we investigated the formation of these deep-seated reservoirs through the comparison between upper and lower slopes.The results suggest that the reservoir of lower slop is highly compacted and has weaker dissolution than the reservoir in the upper slope.Dissolution and micro fractures are the key factors in determining the formation of deep-seated reservoirs.The fluids that caused the dissolution of reservoir can be divided into three stages and sourced from the mixture of deep and basin fluids.A model of reservoir formation and evolution has been set up.Our research could provide an insight for the formation of deep-seated reservoirs in similar geological conditions worldwide.展开更多
基金supported by the PetroChina Science and Technology Major Project(No.2023ZZ0205)the Scientific research and technology development project of CNPC(Nos.2021DJ04 and 2021DJ0401)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA14010301)the National Natural Science Foundation of China(Grant No.41702138).
文摘The characteristics and formation mechanism of clastic reservoirs have a significant impact on petroleum accumulation in the deep-seated strata of sedimentary basins.Newly drill data indicate that the tight reservoirs in the lower slop of Fukang Sag in the Junggar Basin produce a lot of oil despite being buried extremely deep and with low porosity.By using lithological and geochemical studies,we investigated the formation of these deep-seated reservoirs through the comparison between upper and lower slopes.The results suggest that the reservoir of lower slop is highly compacted and has weaker dissolution than the reservoir in the upper slope.Dissolution and micro fractures are the key factors in determining the formation of deep-seated reservoirs.The fluids that caused the dissolution of reservoir can be divided into three stages and sourced from the mixture of deep and basin fluids.A model of reservoir formation and evolution has been set up.Our research could provide an insight for the formation of deep-seated reservoirs in similar geological conditions worldwide.
