【作者】 马发明；

【导师】 赵金洲； 曾时田； 许可方；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2009， 博士

【摘要】 须家河组气藏是西南油气田分公司“十一五”期间乃至中远期天然气储产量增长的后备基地,是西南油气田分公司二十一世纪能源接替的重要领域。川西须家河组储层孔隙空间以溶蚀孔、裂缝为主,普遍具有低孔、低渗、高含水饱和度、小孔、细喉、高中值压力、不均质性强等特征,属典型的致密/超致密裂缝～孔隙型储层,必须采取有效的增产措施提高低渗区储量动用程度。川西须家河地区存在多种因素致使水力加砂压裂改造的难度很大:储层天然裂缝发育,多裂缝滤失严重;储层岩性细砂岩细粒,硅质胶结较硬,岩石杨氏模量高,地层破裂压力大;储层埋藏深,压裂时管路摩阻大,造成施工压力大等等原因,均可能会受施工压力的限制而无法提高排量导致压裂施工失败。本文针对川西须家河深层致密裂缝性气藏的压裂理论与应用技术研究进行了系统研究,取得了以下主要成果:(1)综合运用岩石力学、弹性力学等理论,建立了泥浆造壁伤害后储层裸眼完井和射孔完井的井壁应力场模型,为致密气藏高破裂压力储层破裂压力预测提供了理论计算方法。(2)通过对PLB区块单井静态和动态岩石力学参数的测试,结合压裂施工资料,建立了该区块岩石力学动静态相关关系式和分层地应力力学模型,得到了单井纵向应力剖面。(3)通过实验对单矿物与常规砂岩酸化酸液体系的反应机理和泥浆浸泡对岩石力学参数的影响研究,运用岩石损伤原理建立了预测酸处理后岩石破裂压力的定量计算模型,能较准确地预测该区块储层的破裂压力(误差＜10%)。(4)系统阐述了多裂缝的形成机理及多裂缝的消除技术,并结合川西须家河的地质特征和工程实际,研究了须家河气藏多裂缝的形成机理和包括支撑剂段塞、压裂材料选择、施工参数优化在内的多种降滤失与多裂缝防治的压裂工艺技术。(5)依据须家河气藏储层物性条件,提出了须家河气藏压裂液体系的性能要求,通过室内实验优选了中高温低摩阻压裂液添加剂,并对优化、调试的压裂液体系进行了综合性能评价;通过实验测试优选了不同类型和不同粒径配比支撑剂,为有效提高川西须家河深层气藏加砂压裂成功率提供了新的思路。(6)研究成果应用于川西PLB气藏加砂压裂改造并首次取得了成功。更多还原

【Abstract】 Xujiahe formation gas reservoir is the candidate base for reserves and outcome growth of Southwest Oil and Gas Field Branch in the period of Eleventh Five-Year Plan and medium-long time; it is also the important energy replacement domain in the 21st century. The majority of pore spaces in western Sichuan Xujiahe formation are emposieu and fracture, it generally has characteristics of low porosity, low permeability, high water saturation, micro pore, mini throat, high median pressure, strong heterogeneity; and it is the typical tight/hyper-tight fractured and pored reservoir, so it needs taking effective stimulation to improve producing reserves of low permeability layer. In western Sichuan Xujiahe area, it has many difficulties in implementing hydraulic sand fracture such as the well-developed natural fracture, the multi-fracture grave filtration; fine sandstone and hard siliceous cement, the high Young’s modulus ,high fracture pressure; high treating pressure caused by high burial depth and the great friction of tube in during fracture,et.al. which cause falilure of fracture because it has no method to improve the discharge rate. This paper takes systemically research on fracturing theory and applied technology of deep zone tight-fractured gas reservoir in western Sichuan Xujiahe formation, and has acquired the following results:(1)By synthetically using of rock mechanics and elasticity, it forms wellface stress field model of the barefoot completion and the perforated completion after mud damaged formation, which provides theory calculate measure of reservoir fracture pressure predict for the high fracture pressure of tight gas reservoir.(2)Based on dynamics and static state rock mechanics testing of PLB block, associated fracturing data, builted up relational expression of the block dynamics and static state rock ,and model of layered earth stress, and acquires vertical layered stress section of the single well.(3)The reaction mechanism between individual mineral and conventional sandstone acidizing acid by laboratory experimental test,and the influence of mud immerse on rock mechanics. quantitative computing methods of forecasting the fracture pressure after acid pretreatment by using the principle of rock damage mechanics,which can relatively accuracy forecast fracture pressure of the block(inaccuracy less than 10%).(4)It systemically describes multi-fracture generating mechanism and eliminating technology, with the consideration of geologic characteristic and engineering practice in Xujiahe area, and do some research on multi-fracture generating mechanism and many technologies of reducing filtration and preventing multi-fracture, which include proppant slug, selection of fracturing materials, optimizing treating parameters etc.(5)According to gas reservoir physical properties in Xujiahe formation area, it brings forward performance requirements of fracturing fluid system, optimizes medium-high temperature and low friction fracturing fluid additive through laboratory experiment, and evaluates overall performance of this optimized and debugged fracturing fluid. By Testing proppant conductivity under various forms and grain diameter match, which provides new method for optimizing proppant in Xujiahe deep-seated gas reservoir fracturing.(6)research outcome applied to the gravel input fracture reform of western Sichuan PLB formation and acquired the first successful.更多还原