摘要
对于遮挡层(隔层)较差的储层(尤其对于薄层储层)压裂,广泛应用人工隔层技术有效控制压裂裂缝高度。文章假定浮式、沉式控缝剂在裂缝端部分别形成具有一定厚度和强度(梯度)的人工隔层获得了裂缝剖面上的应力分布。应用线弹性断裂力学张开型裂缝静态延伸准则,首次建立了人工隔层条件下的裂缝高度延伸控制方程,定量描述缝流体压力对裂缝高度的控制作用和人工隔层对裂缝高度延伸的影响。通过编制计算机程序模拟、研究了人工隔层性质对裂缝高度延伸的控制作用,模拟表明人工隔层强度(阻抗)和厚度对于有效控制压裂缝高度都有相当重要的作用。为现场优选控缝剂材料和控缝高压裂设计提供了依据。
Artificial barriers is widely used in order to control hydraulically fracture height propagation in reservoir with worse barrier zone,especial thin pay-zone.In this paper,net pressure distribution in the crack was determined by assuming that the artificial barrier was a zone with some thick and stress gradient(resistant).Then,stress intensity factors in the crack tips were obtained on the basis of fracture mechanics theory,and fracture propagation model was established in accordance with fracture criteria of tensile open crack(Type I).The model described the role of fluid pressure in fracture on the fracture height and affection of artificial barrier on the fracture height propagation.By contrasting the calculation results,it is important for artificial barrier to limit the fracture height growth.This result can be used for choosing barrier material and guiding hydraulically fracture design in oilfield.
出处
《钻采工艺》
CAS
北大核心
2008年第1期68-70,共3页
Drilling & Production Technology
关键词
水力压裂
裂缝高度
人工隔层
hydraulic fracturing,fracture height,artificial barriers
