Affiliation:
1. No.2 Oil Production Plant, SINOPEC Northwest Company, Korla 841000, China
Abstract
Fractured-vuggy reservoirs are a new target in carbonate oil and gas exploration and development. Because of well-developed reservoir bodies, including fractures and caverns, bottom water invasion can be observed in oilfield development, with low utilization efficiency of crude oil in the reservoir. Accordingly, this study focused on the intersection region of the S99 unit of the Tahe fractured-vuggy reservoirs. Based on seismic data, the reservoir bodies can be divided into three types—caverns, fractures, and broken solution pores. Using the same location condition assignment algorithm, four single-type models are fused into a multi-scale discrete three-dimensional geological model of fractured and cavernous reservoirs, and the corresponding fractured-vuggy reservoir model was established for numerical simulation. The single-well historical fitting precision exceeded 85%. Furthermore, the development can be divided into four stages—initial stage of production, peak production stage, liquid control and oil stabilization stage, and scale gas injection stable. Streamlining sweep analysis determined the utilization and distribution characteristics of the remaining oil in the reservoir. It can be concluded that structure, caverns, and fractures were the main controlling factors affecting the remaining oil distribution in the fractured-vuggy reservoir. The fluid exchange among single-well reserve zones was calculated using streamline-based quantitative sweep analysis and interwell flow quantitative analysis method. Through source-sink quantitative analysis, interwell flow relations were derived, and three water breakthrough modes were further concluded: violent flooding, slow ascending of water cut, and low cut or intermittent water production.
Funder
National Science and Technology Major Project of China
Science and Technology Department Project of Sinopec China Petroleum
Subject
Process Chemistry and Technology,Chemical Engineering (miscellaneous),Bioengineering
Reference44 articles.
1. Theories and practices of carbonate reservoirs development in China;Yang;Pet. Explor. Dev.,2018
2. Nairn, A., and Alsharhan, A. (1997). Sedimentary Basins and Petroleum Geology of the Middle East, Elsevier.
3. Technology progress and prospects of enhanced oil recovery by gas injection;Shiyi;Acta Pet. Sin.,2020
4. Practice and knowledge of volumetric development of deep fractured-vuggy carbonate reservoirs in Tarim Basin, NW China;Fangzheng;Pet. Explor. Dev.,2019
5. Experiments on water flooding in fractured-vuggy cells in fractured-vuggy reservoirs;Jing;Pet. Explor. Dev.,2014