Techniques for improving fracture-controlled stimulated reservoir volume in ultra-deep fractured tight reservoirs: A case study of Kuqa piedmont clastic reservoirs, Tarim Basin, NW China  

作　　者：LEI Qun YANG Zhanwei WENG Dingwei LIU Hongtao GUAN Baoshan CAI Bo FU Haifeng LIU Zhaolong DUAN Yaoyao LIANG Tiancheng MA Zeyuan 

机构地区：[1]PetroChina Key Laboratory of Oil and Gas Reservoir Stimulation,Langfang 065007,China [2]PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China [3]PetroChina Tarim Oilfield Company,Korla 841000,China

出　　处：《Petroleum Exploration and Development》2022年第5期1169-1184,共16页石油勘探与开发（英文版）

基　　金：National Science and Technology Major Project(2016ZX05023);PetroChina Science and Technology Major Project(2018E-1809)。

摘　　要：Based on analysis of the reasons for low efficiency and low production after fracturing of some wells in the ultra-deep fractured tight reservoirs of the Kuqa piedmont zone, Tarim Basin and the matching relationship between the in-situ stress field and natural fractures, technological methods for creating complex fracture networks are proposed. Through theoretical study and large-scale physical simulation experiments, the mechanical conditions for forming complex fracture network in the Kuqa piedmont ultra-deep reservoirs are determined. The effectiveness of temporary plugging and diversion, and multi-stage fracturing to activate natural fractures and consequently realize multi-stage diversion is verified. The coupling effect of hydraulic fractures and natural fractures activating each other and resulting in "fracture swarms" is observed. These insights provide theoretical support for improving fracture-controlled stimulated reservoir volume(FSRV) in ultra-deep tight reservoirs. In addition, following the concept of volume fracturing technology and based on the results of fracture conductivity experiments of different processes, fracturing technologies such as multi-stage fracture-network acid fracturing, "multi-stage temporary plugging + secondary fracturing", fracturing of multiple small layers by vertically softness-and-hardness-oriented subdivision, and weighted-fluid refracturing are proposed to increase the FSRV. New environment-friendly weighted-fluid with low cost and new fracturing fluid system with low viscosity and high proppant-carrying capacity are also developed. These techniques have achieved remarkable results in field application.

关 键 词：ultra-deep reservoir tight reservoir natural fracture fracture-controlled reservoir volume temporary plugging secondary fracturing weighted fracturing fluid 

分 类 号：TE357[石油与天然气工程—油气田开发工程]