油气地质与采收率2024，Vol.31Issue(6)：57-64,8.DOI:10.13673/j.pgre.202404005
致密砂岩储层可压裂性测井评价方法
Logging evaluation method of fracturability of tight sandstone reservoirs
徐波 1王振华 2宋婷 3张淑侠 2彭娇1
作者信息
- 1. 西安石油大学 石油工程学院,陕西 西安 710065
- 2. 延长石油(集团)有限责任公司研究院,陕西 西安 710065
- 3. 中国石油长庆油田分公司 第十一采油厂,甘肃 庆阳 745000
- 折叠
摘要
Abstract
The fracturability of reservoirs is an essential parameter for selecting perforation stages and predicting hydraulic fractur-ing effects,but fracturability evaluation for tight sandstone reservoirs lacks unified methods and standards.This paper studies Chang 6 tight sandstone reservoir in an oilfield in the southeastern part of Ordos Basin and optimizes the characterization model of rock me-chanics parameters based on the conventional logging data.The paper analyzes the relationships among reservoir rock brittleness,fracture toughness,in-situ stress difference coefficient,and daily fluid production,establishes the fracturability evaluation model and evaluation standard for tight sandstone reservoirs,and obtains fracture quality factor curves corresponding to logging curves.As a result,a high-precision logging evaluation method for the fracturability of tight sandstone reservoirs was developed.The results in-dicate as follows:① The brittleness index is positively correlated with the fracturability,and the fracture toughness and in-situ stress difference coefficient are negatively correlated with the fracturability.② The fracturing quality factor is greater than 25 for Class I reservoirs,indicating the best fracturability;it is easy to form a complex fracture network during fracturing and belongs to high-quality tight sandstone reservoirs.The fracturing quality factor ranges from 14 to 25 for Class II reservoirs,indicating medium fracturability;it is necessary to use fracturing fluid with low viscosity or keep high net pressure in fractures to form a better fracture network.The fracturing quality factor is less than 14 for class III reservoirs,indicating poor fracturability;an ideal fracture network is usually not formed during fracturing,and fractures are easy to close after fracturing.③ Higher fracturing quality factors of tight sandstone reservoirs indicate better characteristics of artificial fracture morphologies and higher production capacity after fracturing.The evaluation results by the established model are more than 80%consistent with the microseismic fracture monitoring results and production testing results.关键词
致密砂岩/可压裂性/脆性指数/断裂韧性/地应力差异系数/鄂尔多斯盆地Key words
tight sandstone/fracturability/brittleness index/fracture toughness/in-situ stress difference coefficient/Ordos Basin分类
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徐波,王振华,宋婷,张淑侠,彭娇..致密砂岩储层可压裂性测井评价方法[J].油气地质与采收率,2024,31(6):57-64,8.
