水平井压裂二界面脱粘力学模型研究

发布时间：2018-01-24 14:01

本文关键词： 水平井二界面承压能力失效机理　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：吉林油田扶余地区油藏是典型的“三低”油藏,常采用水平井分段压裂技术以达到增产上储目的。由于压裂二界面胶结强度小,压裂时在目的层压开前,二界面已先被压坏形成窜流通道,如果封隔不好将引起层间窜流。因此,压裂过程中二界面承压能力的好坏是评价压裂施工能否成功的关键。压裂二界面的承压能力是设计压裂施工参数的重要指标,参数设计不合理导致压裂后期层间窜流、地层出水、压窜相邻层段等现象,影响后期采油增产措施的实施。本文根据水平井的井身特点,考虑非均匀地应力对水平井井眼的作用,建立了非均匀地应力作用下水平井压裂二界面应力分布计算模型;同时分析压裂过程中井眼内的压力变化对井壁应力分布的影响,建立了压裂过程中水平井二界面应力分布计算模型。建立的水平井压裂二界面脱粘力学模型,可计算不同胶结强度下的二界面脱粘压力以及脱粘长度,同时该模型为分析不同水泥环及地层性质对二界面脱粘长度的影响提供了理论依据。建立的水平井压裂二界面裂缝扩展力学模型,可计算不同失效长度下裂缝沿二界面扩展所需要的压力值,模型的建立为分析不同胶结强度对二界面失效长度的影响提供了理论依据。分析了吉林油田扶余地区水平井二界面胶结质量对其承压能力的影响,并得到了该地区水平井不同胶结强度对二界面脱粘压力、脱粘长度以及失效长度的影响。提出水平井压裂二界面压裂完整性评价原则,分析了不同胶结强度、弹性模量及泊松比下压裂参数对水平井压裂二界面完整性的影响,得出保证二界面压裂完整性的封隔器最小间距,该研究成果可为水平井压裂施工参数的设计提供必要的指导。
[Abstract]:The reservoir in Fuyu area of Jilin Oilfield is a typical "three low" reservoir. The horizontal well fracturing technique is often used to achieve the purpose of increasing production and storage. The second interface has been crushed to form a channeling channel, and if the sealing is not good, it will cause interlaminar channeling. In the process of fracturing, the pressure bearing capacity of two interfaces is the key to evaluate the success of fracturing operation, and the bearing capacity of fracturing interface is an important index for the design of fracturing operation parameters. Unreasonable design of parameters leads to interlayer channeling, formation water flow, pressure channeling adjacent interval and other phenomena in the later stage of fracturing, which affect the implementation of the measures to increase oil production in the later stage. According to the wellbore characteristics of horizontal wells, this paper. Considering the effect of non-uniform ground stress on horizontal wellbore, a calculation model of stress distribution at two interfaces of horizontal well fracturing under non-uniform in-situ stress is established. At the same time, the influence of the pressure variation in the well bore on the wellbore stress distribution during fracturing is analyzed, and the calculation model of the stress distribution at the second interface of the horizontal well during the fracturing process is established, and the mechanical model of the second interface debonding in the horizontal well fracturing is established. The debonding pressure and debonding length of the two interfaces can be calculated under different bonding strength. At the same time, the model provides a theoretical basis for analyzing the influence of different cement rings and formation properties on the second interface debonding length. The pressure values required for crack propagation along the second interface can be calculated under different failure lengths. The establishment of the model provides a theoretical basis for analyzing the influence of different cementing strength on the failure length of the second interface, and analyzes the effect of the quality of the second interface cementing on the bearing capacity of the horizontal well in Fuyu area of Jilin Oilfield. The effects of different cementing strength on the debonding pressure, debonding length and failure length of the two interface in horizontal well are obtained. The evaluation principle of the integrity of the two interface fracturing in horizontal well is put forward, and the different cementing strength is analyzed. The influence of fracture parameters under elastic modulus and Poisson's ratio on the integrity of two fracturing interfaces in horizontal wells is discussed, and the minimum Packer spacing is obtained to ensure the fracture integrity of the two interfaces. The research results can provide necessary guidance for the design of fracturing parameters in horizontal wells.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357;TE243

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