泥页岩裂缝性油藏非稳态产能影响因素

Influence factors of unsteady productivity for fractured shale reservoir

李清泉 王新海 刘洪 尹虎 任飞 杨锋 张磊

中国石油大学石油工程教育部重点实验室，北京 102249 中国石油冀东油田公司勘探开发研究院，河北 唐山 063004 陕西延长石油（集团）延长油田股份有限公司直罗采油厂，陕西 延安 727500 长江大学油气资源与勘探技术教育部重点实验室，
湖北 荆州 434023 中国石油塔里木油田公司，新疆 库尔勒 841000

针对裂缝性泥页岩油藏开发的特殊性，基于质量守恒定律，在同时考虑裂缝及压力敏感性的情况下，建立了双孔单渗油藏中多分支垂直裂缝压裂井的数学模型，对其进行无量纲化后，采用隐式差分方法对无因次模型进行求解。根据油藏实际特点，建立地质模型，通过数值模拟计算研究了裂缝分支数、无因次裂缝半长、无因次窜流系数及无因次压敏系数等因素对不稳态产能的影响。研究结果表明，除人为可控的裂缝参数对产能的影响较大外，油藏自身的压敏系数也具有较显著的影响。为此，在该类油藏开发过程中，应在进行压裂方案优选以获取最大产能的同时，合理控制地层压降，以达到良好的开发效果。

In accordance with the development particularity of shale reservoir, a mathematical model has been set up to study the flow in the multi- lateral vertical fractured wells in dual porosity and single permeability reservoir, which is based on the law of conservation of mass and considers both fracture and pressure sensitivity. The model is converted to be dimensionless. And then, numerical solutions of the model are obtained by using implicit difference method. The geological model is established according to the real reservoir characteristics. The effects on unsteady productivity of branch number and dimensionless half length of fractures, dimensionless interporosity flow coefficient and dimensionless pressure sensitive coefficient have been studied through numerical simulation. Research results show that the pressure sensitive coefficient of reservoir itself has a great effect on the productivity except the fracture parameters which can be controlled. Therefore, in the development process of such reservoir, it is necessary to control the pressure decline reasonably to achieve good development results, as choosing an appropriate fracturing scheme to obtain maximum productivity.

10.6056/dkyqt201305018