石油钻采工艺2023，Vol.45Issue(5)：607-615,9.DOI:10.13639/j.odpt.202305033
藻灰岩压裂裂缝扩展规律物理模拟
Physical simulation of fracture propagation patterns in algal limestone fracturing
郑宏林 1马新仿 1林海 2郭得龙 2刘永2
作者信息
- 1. 中国石油大学(北京)石油工程学院
- 2. 中国石油青海油田钻采工艺研究院
- 折叠
摘要
Abstract
In Fengxi block of the Qaidam Basin,the weak surfaces are developed in the algal limestone reservoirs of the Lower Youshashan formation,exhibiting complex lithologies,significant variations in physical properties and strong heterogeneity.The mechanism of fracture propagation during hydraulic fracturing in this area is not well understood.Mineral composition characteristics of the algal limestone were analyzed using rock cuttings electron microscopy scanning experiments,and rock brittleness evaluation based on energy evolution was conducted through triaxial compression experiments.To explore the fracture propagation patterns of algal limestone under different geological and engineering conditions,small-scale true triaxial hydraulic fracturing tests were conducted on algal limestone containing structurally weak surfaces under reservoir temperature and pressure conditions.The pressure curves and fracture morphologies were analyzed.The research results indicate that the algal limestone has a high content of carbonate minerals and shows clear brittle characteristics,with a calculated brittleness index of 0.56 using the energy evolution method.Under experiment conditions of low horizontal stress difference,high injection rate and low fracturing fluid viscosity,the stress-controlled effect on artificial fractures is weakened,the weak structural surfaces are easily activated,and the local curvature of fractures increases,leading to the formation of complex fractures.This study provides a guidance for hydraulic fracturing operations in algal limestone reservoirs.关键词
藻灰岩/压裂/复杂裂缝/岩石脆性/水平应力差/压裂液黏度/泵注排量/物理模拟Key words
algal limestone/fracturing/complex fracture/rock brittleness/horizontal stress difference/fracturing fluid viscosity/pumping displacement/physical simulation分类
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郑宏林,马新仿,林海,郭得龙,刘永..藻灰岩压裂裂缝扩展规律物理模拟[J].石油钻采工艺,2023,45(5):607-615,9.
