摘要
中东地区低渗孔隙型碳酸盐岩油藏开发潜力巨大,但其储层物性差,渗流能力低,压裂改造是解锁其商业潜能的关键手段,对达成中国石油“高速开采、快速回收”的开发目标具有重要意义。本文针对该类油藏压裂改造方式不明确,改造后单井产能差异较大等开发难题,开展了基于物模实验的合理储层改造方式论证和基于数模模拟的改造方式优化设计。通过真三轴物理模拟实验验证了低渗孔隙型碳酸盐岩储层压裂的可行性,明确了胍胶和滑溜水在压裂裂缝形态上的差异性。使用井下全直径岩心制作岩板,基于支撑剂导流能力实验确定了最佳支撑剂粒径和配比。基于中东某油田S油藏测井数据,建立了典型的地质力学模型和数值模拟模型,以净现值为目标,优化了低渗孔隙型碳酸盐岩压裂施工参数并形成配套施工工艺。研究结果表明:对于天然裂缝不发育或发育较少的低渗孔隙型碳酸盐岩储层,可使用水力加砂压裂进行储层改造,室内岩心压裂改造实验显示,利用滑溜水和胍胶的混合压裂液可形成相对复杂的裂缝形态。相同闭合压力下,支撑剂粒径越大,相应的导流能力越大。70~140目粒径支撑剂在30 MPa闭合压力下其导流能力不足3 D·cm。对于S油藏,当压裂段数为6段、射孔簇数为4簇、每段压裂液340 m、每段支撑剂50 m时,压裂效果最好。现场应用结果显示压裂效果良好。该研究成果对中东低渗孔隙型碳酸盐岩油藏经济高效开发具有一定的指导意义。
Low permeability porous carbonate reservoirs in the Middle East have great potential for development,but their attributes are poor and seepage capacity is low.Hydraulic fracturing is one of the key technologies to unlock their commercial potential.It is of great significance for China National Petroleum Corporation to achieve the development goal of"high-speed production and rapid recovery".This paper aims at the problem of hydraulic fracturing mode optimization and large difference in productivity of single well after stimulation of the low permeability porous carbonate reservoirs.A demonstration of reasonable fracturing models based on a lot of experiments was carried out,and numerical simulations were used to optimize the fracturing process.The feasibility of fracturing low permeability porous carbonate reservoirs was verified by true tri-axial experiments,and the differences in fracture morphology between guar and slick water were clarified.Using downhole full-diameter cores to make rock slabs,the optimal proppant particle size and ratio are determined based on proppant conductivity experiments.Based on the mean value of the logging data of the S reservoir in an oilfield in the Middle East,a typical geomechanical model and numerical simulation model were established.To maximize the net present value of production,the fracturing parameters of low permeability porous carbonate rock were optimized and a matched fracturing process was formed.The results of experiments and numerical simulations show that,for low permeability porous carbonate reservoirs with few or no natural fractures,adding sand hydraulic fracture treatment can be used for these reservoirs stimulation.Relatively complex fractures can be formed in low permeability porous carbonate cores by hydraulic fracturing using a mixture of guar and slick water.Proppant conductivity experiments show that the larger particle size of proppant,the greater the corresponding conductivity under the same closing pressure.The particle size of the proppant should not
作者
杨菁
刘辉
宁超众
YANG Jing;LIU Hui;NING Chaozhong(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)
出处
《石油科学通报》
2022年第2期204-212,共9页
Petroleum Science Bulletin
基金
中国石油天然气股份有限公司科学研究与技术开发项目《海外油田开发关键技术研究》(2021DJ3202)资助。
关键词
低渗碳酸盐岩
压裂物模实验
数值模拟
优化设计
low permeability carbonate
fracturing experiments
numerical simulation
optimization design
