Erosion Thickness And Carst Reservoir Distribution Characteristic About T₇⁴ Interface In 3D Area Of Ka1 Block, Tarim Basin

Through the analysis of tectonic evolution, strata and sedimentary in early Paleozoic about Tazhong uplift, Yijianfang Formation was erosion completely and Yingshan formation was erosion different level in different area in middle-caledonian. In the early of Ordovician Period Lianglitage formation overlapped on the Yingshan formation. The significant unconformity surface between Yingshan and Lianglitage formation is T₇⁴ interface. Erosion thickness about the unconformity surface of well Zhong12 and well Zhong17 in 3D area Ka1 block is 326 and 272 meters by the fundamental principle of stratigraphic correlation. Calculating the erosion thickness in the northernâ…¡fault zone 3D area, the erosion thickness in the area of well zhong1 - well zhong12 to northern fault ofâ…¡fault zone is higher than its in the area of well zhong11 - well zhong19 fault-anticline trap. In other area the erosion thickness about T₇⁴ interface would be lower relatively. Dividing the palaeogeomorphology units by the remained thickness of Yingshan formation,â…¡fault zone was the carst highland and the southeast orientation from well zhong1 - zhong17 to well zhong12 was carst slope, other area was carst low-lying land. Most of the possible carbonate reservoir points identified by"strong reflection"and"string of beads"are located in the higher erosion thickness area and carst slope. Analysis of the reservoir characteristic about Yingshan formation and its correlation between wells, the reservoir of Yingshan formation about No.5 trap in the ka1 block would be better such as well zhong1 and well zhong17. Then its would be well zhong18 and zhong12. But in the western of the TZ10 fault zone the reservoir of Yingshan formation about zhong11 fault-anticline trap would be bad, such as well zhong11 and well zhong19 which reservoir are classified asâ…¢. The reservoir of Yingshan formation about well zhong15 also is classified asâ…¢, this should be relationship with palaeogeomorphology before sediment of lianglitage formation. So the carst slope could be the best carbonate reservoir area.