Reservoir characteristics and main controlling factors of the Leikoupo gas pools in the western Sichuan Basin

被引:0
作者
Xiao K. [1 ]
Li H. [1 ]
Duan Y. [2 ]
Zhang Y. [2 ]
Liu L. [2 ]
机构
[1] Key Laboratory for Marine Oil and Gas Exploitation, Sinopec Exploration & Production Research Institute, Beijing
[2] Sinopec Southwest Oil & Gas Company, Chengdu, 610041, Sichuan
关键词
Controlling factors; Dolomite; Fracture-pore type reservoir; Middle Triassic; Pore-type reservoir; Reservoir characteristics; Sichuan Basin; Western Sichuan gas field;
D O I
10.3787/j.issn.1000-0976.2019.06.004
中图分类号
学科分类号
摘要
Significant progress in natural gas exploration in the Middle Triassic Leikoupo Fm of the western Sichuan Basin have been achieved by Sinopec in recent years, and the western Sichuan gas field has become the key block for the increase of reserves and output of Sinopec in natural gas exploration and production in the 13th Five-Year Plan. For further understanding of the reservoir characteristics and the controlling factors of the Middle Triassic Leikoupo Fm reservoir in western Sichuan gas field, reservoir characteristics and the controlling factors of reservoir development in Shiyangchang-Jinma-Yazihe area were investigated based on detailed observation of rock slices and cores, utilizing porosity, permeability and intrusive mercury analysis in combination with well logging interpretation results. The research results show that: (1) the dolomite reservoirs of tidal flat facies were developed in the Leikoupo Fm of this area, which can be divided into an upper reservoir section, a lower reservoir section and an interlayer section; (2) the upper reservoir section is relatively simple in reservoir lithology, reservoir space type and pore-throat assemblage, and the main lithology is microcrystalline (crystal powder) dolomite with mainly pore-type reservoirs, and relatively high-quality microcrystalline dolomite reservoirs with medium porosity and low permeability are locally developed; (3) the lithology, reservoir space type and pore structure of the lower reservoir section are complex and strongly anisotropic, and the reservoirs are mainly of fracture-pore type with (extremely) low porosity and permeability; (4) the reservoirs are vertically anisotropic, and different types of thin reservoirs are interbedded. The thickness of effective reservoirs is between 30 m and 56.6 m. The total thickness and overall physical properties of the the lower reservoir section is superior to the upper section; (5) the distribution of dolomite is controlled by the flat and algae flat microfacies as well as dolomitization, which lay a lithological foundation for reservoir development; (6) multi-stage quasi-syngenetic dissolution controlled by high-frequency intertidal cycles is the key factor for the development of high-quality reservoirs; (7) hydrocarbon filling during the burial stage inhibits the formation of scale cements, and makes the early-formed pores better preserved. © 2019, Natural Gas Industry Journal Agency. All right reserved.
引用
收藏
页码:34 / 44
页数:10
相关论文
共 28 条
  • [1] Sun W., Liu S., Cao J., Deng B., Song J., Wang G., Et al., Analysis on the formation conditions of large-scale marine deep and super-deep strata gas fields in the middle-northern segments of western Sichuan Superimposed Basin, China, Acta Petrologica Sinica, 33, 4, pp. 1171-1188, (2017)
  • [2] Li S., Xu G., Song X., Forming conditions of Pengzhou large gas field of Leikoupo Formation in Longmenshan piedmont tectonic belt, western Sichuan Basin, China Petroleum Exploration, 21, 3, pp. 74-82, (2016)
  • [3] Ning M., Liu S., Gong W., Prediction of dolomite reservoir distribution on top of Triassic Leikoupo Formation in Chuanxi Depression, China Petroleum Exploration, 20, 3, pp. 30-37, (2015)
  • [4] Li R., Hu H., Xu G., Wang Q., Song X., Long K., Influences of dolomitizationon reservoirs of Upper T<sub>2</sub>l<sub>4</sub> of Leikoupo Formation in Western Depression, Sichuan Basin, Xinjiang Petroleum Geology, 38, 2, pp. 149-154, (2017)
  • [5] Li H., Hu X., Shi Y., Xiao K., Jia Y., Wei X., Et al., Sequence division and controlling factors of reservoir development of the 4th Member of Leikoupo Formation in foreland of Longmen Mountains in the Western Sichuan Depression, Sichuan Basin, Oil & Gas Geology, 38, 4, pp. 753-763, (2017)
  • [6] Wu S., Li H., Long S., Liu Z., Wang C., Zhang J., A study on characteristics and diagenesis of carbonate reservoirs in the Middle Triassic Leikoupo Formation in Western Sichuan Depression, Oil & Gas Geology, 32, 4, pp. 542-550, (2011)
  • [7] Lu Y., Ni C., Zhang J., Gu M., Sun Q., Liu Z., Et al., Favorable sedimentary facies zones and lithofacies palaeogeography of Middle Triassic Leikoupo Formation in Sichuan Basin, Marine Origin Petroleum Geology, 18, 1, pp. 26-32, (2013)
  • [8] Li L., Tan X., Zhou S., Zou C., Sequence lithofacies paleography of Leikoupo Formation, Sichuan Basin, Journal of Southwest Petroleum University (Science & Technology Edition), 34, 4, pp. 13-22, (2012)
  • [9] Chen L., Shen Z., Hou F., Fang S., Formation environment of Triassic evaporate rock basin and dolostone reservoirs in the Sichuan Basin, Petroleum Geology & Experiment, 32, 4, pp. 334-340, (2010)
  • [10] Wang Q., Song X., Wang D., Long K., Reservoir characteristics and formation mechanism of the 4th Member of the Leikoupo Formation in Longmen Mountain front, Petroleum Geology & Experiment, 39, 4, pp. 491-497, (2017)