致密气藏压裂水平井产能评价研究

发布时间：2018-10-18 09:25

【摘要】：国内外专家学者对低渗透致密气藏的开发日益关注。低渗透致密气藏储量巨大,开发潜力高,但是由于单井自然产能低,常采用水平井分段压裂技术对其进行增产改造,压裂后产能评价对正确评估和分析其压裂效果十分重要。本文对致密气压裂水平井产能评价理论模型与方法进行了深入研究,完成了以下主要工作：(1)充分调研分析了国内外试井分析方法、产能评价方法、水平井分段压裂技术和水平井裂缝特征及渗流机理等相关技术现状。(2)利用双重介质气藏渗流理论,以油层渗流力学和油藏工程为理论依据,基于Warren—Root模型,推导出了考虑井筒储集效应、表皮效应以及天然裂缝影响的无限导流上下边界封闭侧向无限大分段压裂水平气井的现代试井模型。(3)采用Laplace变换将渗流微分方程转换到拉氏空间、运用Stehfest数值反演到实空间、利用点源法解决压裂缝的叠加、结合Duhamel原理考虑表皮效应和井筒储集效应,并应用Matlab编制程序计算求解了无限导流上下边界封闭侧向无限大分段压裂水平气井的现代试井模型。(4)基于压力响应求解了致密气藏水平井压裂后的采气指数,利用Orgin制图软件绘制了井底无因次压力、无因次压力导数双对数典型图版以及采气指数样版曲线,总结了压力响应特征,并对比分析了敏感性因素。(5)结合压力响应和采气指数图版,优化了地层参数以及裂缝参数,以此建立了一种致密气藏压裂水平井产能评价新方法。
[Abstract]:Experts and scholars at home and abroad are paying more and more attention to the development of low permeability tight gas reservoirs. The low permeability tight gas reservoir has huge reserves and high development potential, but due to the low natural productivity of single well, the horizontal well fracturing technology is often used to increase production and reconstruct it. The evaluation of productivity after fracturing is very important to correctly evaluate and analyze the fracturing effect. In this paper, the theoretical model and method of productivity evaluation for tight pressure split horizontal wells are studied in depth. The main works are as follows: (1) well test analysis methods and productivity evaluation methods at home and abroad are fully investigated and analyzed. Horizontal well fracturing technology, fracture characteristics and percolation mechanism of horizontal wells, etc. (2) based on the theory of reservoir percolation mechanics and reservoir engineering, based on Warren-Root model, the theory of dual medium gas reservoir percolation is used. A modern well test model for horizontal gas wells with infinite conductivity upper and lower boundaries closed and infinite segmental fracturing is derived considering wellbore reservoir effect, skin effect and natural fracture effect. (3) the differential equation of seepage flow is transformed into Lagrangian space by Laplace transform. Using Stehfest numerical inversion to real space, using point source method to solve the superposition of compressive fracture, considering skin effect and wellbore reservoir effect combined with Duhamel principle, The modern well test model for horizontal gas wells with infinite conductivity and upper and lower boundaries is calculated by using Matlab program. (4) based on the pressure response, the gas recovery index of fractured horizontal wells in dense gas reservoirs is calculated. The curves of dimensionless pressure, dimensionless pressure derivative, double logarithm of dimensionless pressure derivative and gas recovery index were drawn by using Orgin software, and the pressure response characteristics were summarized. The sensitivity factors are compared and analyzed. (5) combined with pressure response and gas recovery index chart, the formation parameters and fracture parameters are optimized, and a new method for evaluating the productivity of fractured horizontal wells in tight gas reservoirs is established.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE328

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