【作者】 宋毅；

【导师】 伊向艺；

【作者基本信息】 成都理工大学 ， 油气田开发工程， 2009， 硕士

【摘要】 压裂技术经过60多年的研究和发展,已经成为一项成熟有效的增产技术而广泛应用。近年来我国新增的探明储量中约2/3为低/特低渗油气藏,压裂是该类油气藏勘探开发的必要措施和有效手段。同时压裂也是一项高投入、高风险的技术,单井的作业成本一般在数十万至数百万元;如果对储层特征认识不足、选井选层不当、入井材料选择不合理、施工设计不合理、施工质量不达标等都可能导致施工失败或压裂以后不能取得理想增产效果的情况,更有甚者可能导致本来有一定产能的油气井压裂后产能降低或没有产能的严重后果;对于注水开发的油田,如果储层改造以后形成的裂缝方位与油藏开采的注采井网不匹配的话,会给开发后期调整带来很大的影响。全面、系统、深入地研究压裂中可能遇到的各种风险,研究控制风险的方法,从降低风险的角度指导压裂的全过程,对于提高压裂的成功率和有效率、降低压裂投资风险、提高油田经济效益有重要意义。本文在前人研究的基础上,全面、系统的总结了压裂中可能面临的各种风险,以及风险发生的原因及控制风险的方法,初步尝试构建了压裂风险控制体系。为了研究人工裂缝对油藏生产动态的影响,运用油藏数值模拟研究了五点法井网油水井同时压裂裂缝长度有利和不利情况下裂缝长度对生产动态的影响。为了提高压裂风险决策的科学性和决策效率,将模糊综合评价方法引入到压裂风险决策中,构建了压裂风险评价的指标体系,综合运用层次分析法和专家经验法确定各项指标的权重,并通过实例说明如何运用模糊综合评价方法进行压裂风险决策,并且编制了基于模糊综合评价的压裂风险决策软件。最后结合靖边气田实施的交联酸携砂酸压新工艺,研究了该工艺可能面临的各种风险和降低风险的方法,运用该工艺先后对6口井进行了现场施工,施工的成功率和有效率均达到100%,压后最大产能37.0236×104m3/d,最大加砂量25.1m3。运用灰色关联分析法研究了影响该地区酸压后产能的主控因素,研究表明对于该地区而言影响携砂酸压产能的主控因素为有效厚度、施工规模和地层压力,可以为该地区下一步的选井选层和施工设计提供指导。更多还原

【Abstract】 Fracturing has become a mature and effective technology widely used throughmorethan60 years ofresearch anddevelopment. Sincetwothirds ofthenewly-foundproved reserves in china are low or ultra-low permeabilityreservoirs, fracturingis thenecessary measures and effective means of this kind of reservoirs’exploration anddevelopment. At the same time, fracturing is a high investment and high risktechnology.and the operation cost for a single well is about hundreds of thousands tomillions Yuan. If we have not an full understanding to the reservoir characteristics, ifthewellandlayerselectionisunreasonable,iffracturingliquidandproppantselectionis not appropriate, if construction design is improper, if Construction quality is notreach the standard ,all of these may result construction failure or can not achieve thedesired yield,To make matters worse, it mayresult the well deliverabilityfall or haveno deliverability. To the waterflood development oil field, if the fracturing fracturedirection don’t match the flooding well network, it may bring great difficulties to thedevelopment plan adjustment. Making a complete , systematic and deep study to therisks that may be encountered in fracturing and making measures according to theconcrete situation to guide the whole course of fracturing from the reduce risk angle,have an important significance for improveing the succeeding rate and efficiencyrateof construction, decreasing the investment risk and advancing economy benefit.Based on the predecessors’ study, this paper comprehensively and systematiclysummarized the risks that fracturing may counter, the cause that brought about therisks, and discussed the method to control risks. at the same time, the paperpreliminary attempt to establish a system of fracturing risk control,and studied themethod of fracturing risk decision-making. In order to study the influence ofhydraulic fracturing on the production dynamic of reservoir, the paper study theinfluence of fracturing length on the production dynamic of five-spot flood system in the situation of the favorable and unfavorable fracturing direction with the method ofreservoir simulation. To realize the science and effectiveness of the hydraulicfracturingriskdecisionmaking,themethodofFuzzycomprehensiveevaluation(FCE)has been used. The paper constructed an evaluation index system of hydraulicfracturing risk , and a compositive method of Specialist Grading and AnalyticalHierarchy Process (AHP) was used to confirm the index weights.Besides, through acomplete example,it has explained how to use Fuzzycomprehensive evaluation(FCE)to make assessment for hydraulic fracturing risks,on the basis of which, a softwarewas programmed. At last, as for the new technology of the proppant-carrying acidfracturing of cross-linking acid fluid which was used in jingbian gas field, the paperanalyses the risks during the process of its implementation and proposed methods todecrease the risk.6 wells have been treated by this technology, with the constructionsuccess ratio 100%, and the construction availability ratio 100%.The maximaldeliverabilityafterhydraulicfracturingis37.0236×104m3/d.andthemaximalproppantvolume is 25.1m3.At the same time, in order to analyze the main influencing factorsand influence degree of all kinds of factors to deliverabilityafter hydraulic fracturing,grey correlation analytical method was applied. The result shows that effectivethickness, operation scale and formation pressure are the main influencing factors,which has certain direction significance to the well and layer selection, fracturingdesign.更多还原