基于微震监测与地应力分析的低渗油藏压裂致缝解释研究

发布时间：2018-11-03 16:36

【摘要】：近年来，低渗透储层油气藏逐渐成为世界石油产量增加的重要组成部分。由于低渗透油气储层具有“三低”（低丰度、低压、低产）的特点，其开发难度大，水力压裂微震监测技术是目前国内外比较流行的一种改造低渗透油气田的有效方法。准确地获取压裂过程中产生的裂缝方位和几何形状等信息可以优化井网布置、优化注水方案、对油气产量进行评估等，，有效地指导油气田勘探开发。现场油气田压裂过程中，准确地掌握水力裂缝的形态至关重要。目前，国内在水力裂缝监测方面开展了很多工作，但在裂缝解释方面的研究较少。本文基于水力压裂微震监测裂缝技术，以准确解释水力压裂中裂缝的方位、几何参数信息为研究目标，结合压裂现场地应力分析对微震监测反演出的震源点进行裂缝轮廓描绘，确定出裂缝的延伸方向，并对其做出合理的解释。本文提出的裂缝解释方法在现场压裂实验裂缝解释中取得了理想的效果。本文围绕选题的依据和意义分别分析了水力压裂裂缝监测技术和微地震裂缝监测技术在国内外的研究现状。比较直接近井筒裂缝监测、分布式声传感裂缝监测和微震裂缝监测等方法的裂缝监测能力后，选择微震监测作为本文获取裂缝信息的方法。为实现课题的研究目标，本文首先进行了微震裂缝监测技术的研究，分别对微震监测的理论基础、微震监测方法选择及微震监测系统进行了详细叙述，对微震裂缝监测系统进行了总体设计。由于水力压裂裂缝的形态和方位与地应力分布密切相关，本文对地应力相关技术进行了研究。从地应力的基本概念入手，总结了其分布规律、影响因素及获取方法。本文重点分析了压裂裂缝产生机理和其形态的影响因素。从力学的角度研究了压裂裂缝的造缝机理，在理论上给出产生垂直裂缝与水平裂缝的条件。在裂缝形态的众多影响因素中，系统地分析了地应力、断层、天然裂缝以及井底压力曲线对水力裂缝形态的影响。最后，针对山西省娄烦县开展的现场水力压裂微震监测裂缝实验，对压裂区域现场地应力进行了详细分析，通过实验区域的现场地应力状态与微震监测结果相结合确定出了裂缝的延伸方向和轮廓，计算出裂缝几何参数。现场压裂实验中，通过地应力状态分析出的裂缝延伸方向与微震监测获取的裂缝方向是相符的。
[Abstract]:In recent years, low permeability reservoirs have gradually become an important part of the increase of world oil production. Because low permeability oil and gas reservoirs have the characteristics of "three low" (low abundance, low pressure and low production), it is difficult to develop them. Hydraulic fracturing microseismic monitoring technology is an effective method for reforming low permeability oil and gas fields at home and abroad. Accurately obtaining the information of fracture azimuth and geometric shape during fracturing can optimize well pattern layout, optimize water injection scheme, evaluate oil and gas production, and effectively guide exploration and development of oil and gas fields. It is very important to accurately understand the shape of hydraulic fracture during field fracturing. At present, a lot of work has been done in hydraulic fracture monitoring in China, but there are few researches on fracture interpretation. Based on the fracture monitoring technology of hydraulic fracturing microseismic, with the aim of accurately explaining the orientation and geometric parameter information of fracture in hydraulic fracturing, and combining with in-situ stress analysis on the site of fracturing, this paper describes the fracture profile of the source point of microseismic monitoring reverse performance. The extension direction of the fracture is determined and reasonable explanation is made. The fracture interpretation method proposed in this paper has achieved ideal results in fracture interpretation of field fracturing experiments. In this paper, the research status of hydraulic fracturing fracture monitoring technology and micro-seismic fracture monitoring technology at home and abroad is analyzed according to the basis and significance of the selected topic. After comparing the ability of direct near wellbore fracture monitoring, distributed acoustic sensing fracture monitoring and microseismic fracture monitoring, microseismic monitoring is selected as the method of obtaining fracture information in this paper. In order to realize the research goal of the subject, this paper first carries on the research of the microseismic crack monitoring technology, respectively to the microseismic monitoring theory foundation, the microseismic monitoring method choice and the microseismic monitoring system has carried on the detailed description. The overall design of microseismic crack monitoring system is carried out. Because the shape and orientation of hydraulic fracturing fracture are closely related to the distribution of in-situ stress, the in-situ stress correlation technology is studied in this paper. Starting with the basic concept of in-situ stress, the distribution law, influencing factors and obtaining methods are summarized. In this paper, the formation mechanism of fracturing fracture and the influencing factors of its shape are analyzed. The fracture forming mechanism of fracturing fracture is studied from the point of view of mechanics, and the conditions for producing vertical fracture and horizontal fracture are given theoretically. Among the many influencing factors of fracture form, the influence of ground stress, fault, natural fracture and bottom hole pressure curve on hydraulic fracture morphology is analyzed systematically. Finally, according to the field hydraulic fracturing microseismic monitoring fracture experiment carried out in Loufan County, Shanxi Province, the in-situ stress in the fracturing area is analyzed in detail. By combining the in-situ stress state of the experimental area with the results of microseismic monitoring, the extension direction and contour of the fracture are determined, and the geometric parameters of the fracture are calculated. In the field fracturing experiment, the fracture extension direction analyzed by in-situ stress state is consistent with the fracture direction obtained by microseismic monitoring.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.11

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