低渗透油藏分段压裂水平井布缝方式优化

Optimization of fracture laying patterns of horizontal well in multi-stage fracturing of low permeability reservoir

朱世琰 李海涛 阳明君 罗伟 黄诚

西南石油大学石油工程学院，四川 成都 610500

College of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, China

为提高压裂改造效果，须优选出合理的裂缝参数。目前国内外优选裂缝参数时，只对裂缝条数、长度、间距、导流能力进行优化研究，没有考虑水平井裂缝布放方式对压裂水平井产能和含水率的影响。为此，文中以某低渗透油藏七点注采井网单元为例，采用数值模拟方法，在水平井分段压裂裂缝参数单因素分析基础上进行水平井布缝方式优化研究，评价了裂缝参数对井网单元开发指标的影响，最后优选出合理的水平井分段压裂裂缝参数。研究结果表明：考虑注水井的影响，为避免水突进，水平井布缝时，裂缝要错开注水井排布，靠近注水井的裂缝要短些，可以不等间距、不等长度排布，在获得较高产能的同时保证含水率也较低；合理的水平井布缝方式可提高单井产量和区块采出程度，使含水率上升缓慢，可提高水平井分段压裂改造效果和经济效益。该研究为同类油藏压裂施工设计提供了有效依据。

In order to improve the fracturing effect, it is necessary to optimize appropriate fracture parameters. At present, the optimization of fracture number, fracture length, fracture spacing and fracture conductivity only are studied, but the influence of fracture laying patterns on productivity and water cut of the fracturing horizontal well is not considered. So taking a certain seven-spot injection-production pattern in low permeability reservoir as an example, by means of reservoir numerical simulation, the optimization of fracture laying patterns is studied on the basis of single factor analysis on fracture parameters of the multi-stage fracturing horizontal well. At the same time, the effect of fracture parameters on development index of the well pattern unit is evaluated, and reasonable fracture parameters are optimized. The results show that taking injection wells into account and keeping from water breakthrough, fractures are arranged staggering injection wells and fractures near to injection wells are shorter on the optimization of fracture laying patterns. Fractures are also placed with unequal fracture length and fracture spacing, which can not only obtain higher productivity but also have lower water cut. Reasonable fracture laying patterns can improve single well production and block degree of reserves recovery, lead to water cut to rise slowly, and be benefit for enhancing horizontal well multi-stage fracturing effect and economic benefit, which provides effective foundation for the fracturing operation design of similar reservoirs.

10.6056/dkyqt201303025