双层油藏中部分射开直井不稳态渗流研究

发布时间：2018-04-18 16:04

本文选题：双层油藏 + 部分射开　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：油气田开采技术和钻井技术的逐渐进步,使我们发现了各种各样类型的油气藏。对于我们已经发现的不同类型的油气藏,包括海上油气田、严重水锥和气顶的油气藏、各向异性因子很大的油气藏、低渗透油气藏、高含水高采出的老油田等,直井开采方案受很多因素限制,开采效果不好,所以导致斜井、定向井以及部分射开井的应用越来越多。采用斜直井的钻井方法开发特殊类型油气藏,这样的油田现场实际例子很多。一方面是由于油气渗流的渗流面积可以通过钻遇斜直井的方式,大大地得到增加,从而来提高油气田产量;另一方面是因为我们发现了很多不同地质条件和埋存条件下的不同油藏,这些油藏厚度、渗透率等渗流物性条件不尽相同。由于单层油藏空间小圆汇解比点源解更贴近于生产实际,本文联合采取Laplace变换和Fourier有限余弦积分变换,在Laplace变换域中求得不稳态渗流过程中小圆汇压力分布,再通过stehfest数值反演方法,求得时空间单层油藏小圆汇压力解。得到的解可以为论文后续推演涉及到的部分射开直井和斜井直线分布汇等问题提供一个解析求解的理论基础。在单层空间小圆汇解的基础上,通过推导,建立了无限延伸单层油藏部分射开直井的渗流数学模型,利用Laplace和傅里叶变换,求得单层油藏压力解和产量,并与Bilhartz曾经给出的有限差分计算的数值模拟结果,进行了井壁压力的实例验证。在无限延伸单层油藏解析解的基础上,建立无限延伸双层油藏部分射开井模型,求解和计算了无限延伸边界双层油藏部分射开直井无量纲压力和产量,并选取商业软件Intepreter中部分射开直井的不稳定试井实例数据并对计算结果进行了验证。接着计算了圆形封闭边界下双层油藏部分射开直井的压力和产量,并通过积分平均解决参考点问题,加快了计算速度。接着进行了产量递减分析和晚期拟稳态渗流特征的分析。最后,在单层油藏部分射开直井圆汇解的基础上,沿斜直线积分,得到带有角度的单层油藏部分射开斜井压力解。并对井斜角、局部射开程度、井斜长和不同油藏厚度对单层油藏部分射开斜井井壁压力的影响进行了分析。
[Abstract]:With the development of oil and gas production technology and drilling technology, various types of oil and gas reservoirs have been discovered.For the different types of oil and gas reservoirs we have discovered, including offshore oil and gas fields, severe water cone and gas cap reservoirs, oil and gas reservoirs with high anisotropy factors, low permeability reservoirs, old oil fields with high water cut and high recovery, etc.Due to the limitation of many factors and the poor production effect, the application of inclined well, directional well and partial shot well is more and more.There are many practical examples in the field of developing a special type of oil and gas reservoir by using the drilling method of inclined straight well.On the one hand, the percolation area of oil and gas percolation can be greatly increased by drilling and meeting oblique vertical wells, thus increasing the oil and gas field production.On the other hand, we have found many different reservoirs under different geological conditions and buried conditions, which have different percolation properties such as thickness and permeability.Because the small circle solution in single layer reservoir is closer to the production practice than the point source solution, the pressure distribution of small circle sink in the Laplace transform domain is obtained by using Laplace transform and Fourier finite cosine integral transform.Then the pressure solution of small circle in time space single layer reservoir is obtained by stehfest numerical inversion method.The obtained solution can provide a theoretical basis for the analytical solution to the problems of linear distribution of vertical and inclined wells which are involved in the subsequent derivation of the paper.On the basis of the small circular solution in single layer space, the mathematical model of percolation of infinite extended single layer reservoir with partial shooting straight well is established. The pressure solution and output of single layer reservoir are obtained by Laplace and Fourier transform.With the numerical simulation results of finite difference calculation given by Bilhartz, an example is given to verify the wellbore pressure.Based on the analytical solution of infinite extension single layer reservoir, a partial perforating well model of infinite extended double layer reservoir is established, and the dimensionless pressure and production rate of partial shooting straight well in infinite extended boundary bilayer reservoir are solved and calculated.The unsteady well test data of partially shot straight well in commercial software Intepreter are selected and the calculation results are verified.Then the pressure and production rate of the double layer reservoir with circular closed boundary are calculated, and the problem of reference point is solved by integral average, which accelerates the calculation speed.Then the production decline analysis and the analysis of the late quasi-steady seepage characteristics are carried out.Finally, on the basis of the circular confluence solution of the single layer reservoir, the pressure solution of the single layer reservoir with angle is obtained by integrating along the oblique straight line.The effects of inclined angle, local shooting degree, well slant length and different reservoir thickness on the wall pressure of partial shooting inclined well in single-layer reservoir are analyzed.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE24

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