• 油气开发 •

四川盆地涪陵页岩气田江东区块下古生界深层页岩气勘探开发实践与启示

1. 中国石化 江汉油田分公司 勘探开发研究院, 湖北 武汉 430223
• 收稿日期:2020-05-19 出版日期:2021-02-28 发布日期:2021-02-07
• 作者简介:陆亚秋(1969-), 男, 博士、副研究员, 页岩气勘探开发。E-mail: Luyq.jhyt@sinopec.com
• 基金资助:
国家科技重大专项(2016ZX05060);中国石化页岩气“十条龙”科技攻关项目(P18051)

Shale gas exploration and development in the Lower Paleozoic Jiangdong block of Fuling gas field, Sichuan Basin

Yaqiu Lu(), Bang Liang, Chao Wang, Chao Liu, Jing Ji

1. Research Institute of Exploration and Development of Jianghan Oilfield Company, SINOPEC, Wuhan, Hubei 430223, China
• Received:2020-05-19 Online:2021-02-28 Published:2021-02-07

Abstract:

Shale gas exploration and development in China has turned to shales buried in more than 3 500 m deep, posing development challenges with their high-pressure, poor physical properties and reluctance to form complex fracture networks after stimulations. The Jiangdong block, one of the major blocks in the phase-Ⅱ productivity construction of the Fuling shale gas field in the Sichuan Basin, contains shale gas at or deeper than such depth in an area of 57.8 km2, accounting for about half of the total block area. The main targets are the high-quality thin black shale layers (① to ⑤) in the Upper Ordovician Wufeng-Lower Silurian Longmaxi Formations that are rich in carbon, silicon, lamellation and pyrite. By applying an appraisal index system for deep shale gas blocks and an optimized horizontal well location selection method to the shales, we come to the conclusion that the major geological factors influencing the performance of deep shale gas wells are the burial depth, in-situ stress, fracture growth characteristics and dip angle of shale layers. It is therefore recommended that, during horizontal well drilling design, the angle between the wellbore and the minimum principal stress be less than 40° with a level difference between two designed target points (A and B) being kept as less than 300 m as possible. The exploration and development practices in the deep shale in the Jiangdong block have achieved relatively higher test production and recoverable reserves from single wells, which is of realistic guidance and reference for other similar deep shale gas exploration and development in the basin.