MJ气田JP2低渗致密气藏压裂水平井产量递减类型及产能研究

发布时间：2018-01-24 14:47

本文关键词： 低渗致密气藏压裂水平井产量递减产能启动压力梯度　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着常规油气资源量不断减少和全球油气需求量不断增加,非常规油气资源的重要性日益突出。而在非常规气藏中,致密砂岩气资源量占有相当大的比重。众所周知,低渗致密砂岩气藏有低孔低渗、连通性差、存在“启动压力”等特点。目前开发此类气藏的主体技术是压裂水平井技术,该技术通过改善储层的渗流场等来实现气藏增产,但生产实践表明部分低渗致密气藏压裂水平井仍存在着明显的产量递减现象,如何利用压裂水平井技术高效开发此类气藏是目前重要的课题,因此亟需开展低渗致密气藏压裂水平井产量递减规律及产能研究。运用气藏工程、数值模拟方法,结合典型低渗致密气藏—MJ气田JP2气藏静态地质资料和压裂水平井生产动态数据,开展了MJ气田JP2低渗致密气藏压裂水平井产量递减规律及产能研究。首先,分析MJ气田JP2气藏的地质特征、开发特征及当前的主要问题。其次,针对JP2气藏15口典型压裂水平井的动态生产数据,运用现代气井产量递减分析方法,计算气井的控制储量、泄气半径、递减类型、递减率等参数,并开展JP2气藏压裂水平井产量递减原因分析和开发对策探讨。再次,基于低渗致密气藏普遍存在“启动压力”现象,建立考虑启动压力梯度下的低渗致密气藏压裂水平井产能计算公式。然后结合JP2气藏压裂水平井的静态参数范围,对压裂水平井产能影响因素开展敏感性分析。再次,结合JP2气藏实际地质模型,建立低渗致密气藏压裂水平井精细数值模拟模型,利用数值模拟方法研究启动压力梯度对压裂水平井产能的影响规律。然后对水平井段在纵向上的位置、水平井长度,以及压裂缝间距、条数、半长、导流能力等参数对水平井产能影响规律进行了研究,并优选压裂水平井参数及压裂缝参数组合。研究取得的主要结论和认识有：(1)JP2低渗致密气藏15口压裂水平井产量递减明显,主要符合指数递减,平均递减率为53.99%,平均单井控制储量为0.1825×108m3,平均泄气半径为145.37m；(2)建立了考虑启动压力梯度下的压裂水平井产能模型,产能影响因素敏感性分析表明启动压力梯度的存在对压裂水平井产量的影响“不容忽视”,最大可导致气井产量降低56.69%；(3)JP2气藏精细数值模拟研究表明,启动压力梯度最大可导致气井产量降低21.12%,而压裂缝可以有效地减弱启动压力梯度对气井产量的影响；(4)水平井段选择高部位打井有利于气井的增产,而水平井长度和压裂缝间距、条数、半长、导流能力的增加,能不同程度地增加气井产量,但增幅逐渐减小
[Abstract]:With the decrease of conventional oil and gas resources and the increasing global oil and gas demand, the importance of unconventional oil and gas resources is becoming increasingly prominent. It is well known that there are low porosity and low permeability in tight sandstone gas reservoirs with poor connectivity. At present, the main technology of developing this kind of gas reservoir is fracturing horizontal well technology, which can improve the percolation field of the reservoir to increase the production of the gas reservoir. But production practice shows that fracturing horizontal wells in some low-permeability tight gas reservoirs still have obvious production decline phenomenon, how to use fracturing horizontal wells technology to develop such gas reservoirs is an important topic at present. Therefore, it is urgent to study the production decline law and productivity of fractured horizontal wells in low permeability tight gas reservoirs. By using gas reservoir engineering and numerical simulation method, combined with static geological data of JP2 gas reservoir and production performance data of fractured horizontal wells in typical low permeability tight gas reservoir MJ gas field. The production decline law and productivity of fractured horizontal wells in JP2 low permeability tight gas reservoirs in MJ gas field are studied. Firstly, the geological characteristics, development characteristics and main problems of JP2 gas reservoir in MJ gas field are analyzed. Secondly, according to the dynamic production data of 15 typical fracturing horizontal wells in JP2 gas reservoir, the controlled reserves, gas leakage radius and decline type of gas wells are calculated by using modern gas well production decline analysis method. The decline rate and other parameters are analyzed and the production decline of JP2 gas reservoir fracturing horizontal well is analyzed and the development countermeasures are discussed. Thirdly, based on the low permeability tight gas reservoir, the phenomenon of "start-up pressure" is common. A formula for calculating the productivity of fracturing horizontal wells in low permeability tight gas reservoirs considering starting pressure gradient is established, and then the static parameters range of fractured horizontal wells in JP2 gas reservoir is combined. Sensitivity analysis of factors affecting productivity of fractured horizontal well is carried out. Thirdly, combining with the actual geological model of JP2 gas reservoir, the fine numerical simulation model of fracturing horizontal well in low permeability tight gas reservoir is established. The effect of starting pressure gradient on productivity of fractured horizontal well is studied by numerical simulation method. Then, the vertical position, horizontal well length, fracture spacing, number of bars and half length of horizontal well section are studied. The effects of flow conductivity and other parameters on the productivity of horizontal wells are studied, and the combination of fracturing horizontal well parameters and fracturing fracture parameters is selected. The main conclusions and understandings of the study are that the production of 15 fracturing horizontal wells in the low permeability tight gas reservoir is obviously decreasing, which is mainly in accordance with the exponential decline, with an average decline rate of 53.99%. The average controlled reserve of single well is 0.1825 脳 10 ~ 8m ~ 3, and the average leakage radius is 145.37 m; (2) the productivity model of fractured horizontal well considering starting pressure gradient is established. The sensitivity analysis of productivity influence factors shows that the influence of starting pressure gradient on horizontal well production can not be ignored. The maximum gas well output can be reduced by 56.69; The fine numerical simulation of gas reservoir shows that the maximum starting pressure gradient can reduce the gas well production by 21.12%, and the pressure fracture can effectively weaken the effect of the starting pressure gradient on the gas well production. 4) the selection of high position in horizontal well section is beneficial to increase production of gas wells, but the increase of horizontal well length and fracturing spacing, number of bars, half length and conductivity can increase the production of gas wells to varying degrees, but the increase is gradually decreasing.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE348

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