Geology Seminar Series - Dr. Qinlian Wei - Characterization of Pore Texture of Tight Reservoirs

Wed., Apr. 26, 2023 4:00 p.m. - Wed., Apr. 26, 2023 5:00 p.m.

Location: College West Room 237.1

You are invited to attend the last Geology Seminar this semester, it will be an in person seminar:

Topic: Characterization of Pore Texture of Tight Reservoirs: A Case Study of Upper Triassic, Chang 7 Member, SW of Ordos Basin

Date and Time: Wednesday, April 26, 2023 at 4:00 PM

Location: College West Room 237.1

Presenter: Dr. Qinlian Wei, Visiting Scholar, Dept. of Geology, University of Regina

Abstract:

The evaluation of pore structure is critical in understanding reservoir characteristics. This study aims to analyze the microscopic pore structure characteristics of tight reservoirs from various provenances through physical property analysis, casting thin sections, scanning electron microscopy (SEM), and constant-rate mercury injection. The pore-throat parameters of the Chang 7 reservoir were analyzed and compared between the Xin'anbian and the Heshui areas. The results show that intergranular pores dominate the pore type of Chang 7 reservoir in the Xin'anbian area, followed by feldspathic dissolution pores, with high necked and tubular throat content caused by weak compaction and dissolution, respectively. On the other hand, feldspar dissolution pores dominate the pore type of Chang 7 reservoir in the Heshui area, followed by intergranular pores, with high content of tube-bundle throats caused by dissolution and flake-bent flake throats caused by compaction. The difference in pore parameters between the two blocks is minimal, but the difference in throat parameters is significant. Under the same permeability conditions, the throat radius distribution range of Chang 7 reservoir samples in the Heshui area is narrower than that in the Xin'anbian area, with tiny throats contributing significantly to reservoir permeability. Sedimentary hydrodynamic conditions and diagenesis are the primary reasons for the differences in pores, throats, and pore structure parameters of Chang 7 tight reservoirs.

Keywords: Pore type; Pore throat parameter; Pore structure ; Tight reservoir; Ordos Basin