致密储层暂堵转向体积改造技术研究

发布时间：2018-06-26 10:55

本文选题：致密储层 + 多级暂堵　；参考：《西南石油大学》2015年硕士论文

【摘要】：随着全球油气资源消耗量的日益加大,越来越多的目光转移到了非常规致密油气资源的开发。在我国的新疆、四川、长庆等油田均广泛分布有致密砂岩储层和致密碳酸盐岩储层。由于物性差、地质条件复杂,致密储层的开发难度大、投资大、风险大,要实现经济有效开采必须对储层进行改造。而常规压裂形成的对称双翼裂缝改造体积有限,不能充分动用致密油气资源,因此必须引入体积改造技术,实现储层的全方位立体改造。但对于某些巨厚、超深、超高压、超高水平主应力差的难点储层,普通的改造工艺还存在局限性,因此必须探索新的体积改造工艺。本文以此为出发点,提出了采用可降解颗粒和纤维对缝口或裂缝远端进行暂堵,提高井筒和裂缝内净压力,以实现人工裂缝在层间、层内、近井筒处转向,纵向上形成多条裂缝,横向上沟通天然裂缝网络或在主裂缝之外形成分支裂缝,大大提高致密储层的改造体积。具体内容如下： (1)采用理论研究和实验研究相结合的方式探究了固体颗粒和纤维在裂缝中的暂堵机理和暂堵规律,形成了“架桥颗粒+填充颗粒+纤维”的多级暂堵思路。并通过建立架桥颗粒用量和填充颗粒用量计算模型,对颗粒用量进行了优化。 (2)以弹性力学、岩石力学以及水力裂缝与天然裂缝相交作用准则为基础,分别研究了水力裂缝在层问、层内的转向机理和转向条件。不同类型储层和不同转向方式的转向机理、条件、影响因素各不相同。 (3)对近井筒转向的理念和原理进行了详细的阐述,考虑初始人工裂缝诱导应力和井眼应力集中对地应力场的干扰,建立了定向射孔井破裂压力计算模型,分析了破裂压力与射孔角度、水平应力差的关系。 (4)考虑任意裂缝形状、地应力和缝内压力分布的影响,计算了任意形状裂缝的应力强度因子,建立了转向裂缝扩展延伸准则,提出了转向裂缝延伸轨迹和转向距离计算模型,编制了裂缝转向延伸模拟程序,分析了影响新裂缝转向半径的因素。 (5)对暂堵转向体积改造技术的施工工艺进行了初步设计,并给出了具体实现过程,选取典型井,进行了现场验证。通过本文的研究,提出了一种结合固体颗粒和纤维的多级暂堵方法,形成了一套以暂堵为手段,以实现“层间+层内+近井筒”复合转向为目的的体积改造技术,为致密油气藏的经济有效开发提供了新的技术思路。
[Abstract]:With the increasing consumption of oil and gas resources in the world , more and more attention has been paid to the development of unconventional tight oil and gas resources . In China , the tight sandstone reservoir and tight carbonate reservoir are widely distributed in oil fields such as Xinjiang , Sichuan and Changqing .

( 1 ) The temporary plugging mechanism and the temporary plugging rule of the solid particles and the fibers in the cracks are investigated by using the combination of theory research and experimental research , and the multi - stage temporary plugging idea of " bridging particles + filling particles + fibers " is formed .

( 2 ) Based on the criterion of elastic mechanics , rock mechanics and hydraulic fracture and natural fracture intersection , the mechanism and conditions of diversion mechanism and steering condition of hydraulic fracture in layer and layer are studied respectively . The mechanism , condition and influencing factors of different types of reservoirs and different steering modes are different .

( 3 ) The concept and principle of near - wellbore steering are described in detail , considering the initial artificial crack - induced stress and the interference of borehole stress concentration to ground stress field , a calculation model of fracture pressure of directional perforation well is established , and the relation between fracture pressure and perforation angle and horizontal stress difference is analyzed .

( 4 ) Considering the influence of arbitrary crack shape , ground stress and internal pressure distribution , the stress intensity factor of arbitrary shape crack is calculated , the extension criterion of steering crack is established , and the calculation model of steering crack extension and steering distance is proposed . The fracture steering extension simulation program is compiled , and the factors influencing the steering radius of the new crack are analyzed .

( 5 ) The construction technology of temporary diversion volume modification technology is designed , and the concrete realization process is given , the typical well is selected , and the field verification is carried out .

Through the research in this paper , a multi - stage temporary plugging method combining solid particles and fibers is proposed , and a set of volume modification technologies are formed to achieve the purpose of " interlayer + inter - layer + near wellbore " composite steering , which provides a new technical idea for the economic and effective development of dense oil - gas reservoirs .
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357

【参考文献】