稠油热采非牛顿渗流及试井分析

【作者】 刘彬；

【导师】 贾永禄；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2007， 硕士

【摘要】 随着我国油田进入了开发的中后期,能源需求的不断增大和油气勘探的深入,非常规油气藏的勘探开发显得越来越重要。其中稠油以其巨大的储量,对改善我国能源结构、缓解石油供需压力具有重大现实意义。与常规油藏不同,稠油油藏因其富含胶质、沥青质、蜡等高分子聚合物使得稠油流变性有别于一般的牛顿流体,而呈现非牛顿渗流特性,使得稠油难于使用一般常规方法开采,目前应用最广泛的是采用热力法开采。稠油油藏不稳定试井是获取地层特性的一种非常重要的方法;是指导监控稠油开采的重要手段。而目前对于这方面的研究还仅仅基于一般的牛顿流体复合模型,由于稠油油藏流体渗流规律的复杂性使得采用常规的牛顿流体试井方法无可避免的会出现很大的偏差,实际应用还有着很大的局限性。因此,深入开展稠油热采不稳定试井分析理论和解释方法研究,建立适应的试井模型,完善分析方法,为求取稠油油藏特性参数和产能评价提供技术支持,无疑具有十分重要的意义。本文在对国内外非牛顿试井文献进行了广泛调研和认真分析,在前人所积累的研究成果的基础上,针对热采蒸汽吞吐井的试井问题进行了系统的研究。从渗流微观机理上详细推导,建立了更加符合实际的、完善的试井解释模型,求得了相应模型的解,绘制了样板曲线,并作了相应了敏感性分析,同时对于热采蒸气吞吐井定井底压力条件下的流量动态规律作了相应的分析。本文完成的工作主要有;(1)对非牛顿渗流机理及流变性进行了一定的研究,详细推导了非牛顿稠油在多孔介质中渗流的偏微分方程。(2)建立了外区为非牛顿幂律流体,考虑热损失、井筒储集效应、表皮效应和附加压力降的两区复合油藏的试井模型,分别在外边界条件为无穷大、圆形封闭和圆形定压的情况下进行求解,绘制了相应的样板曲线并进行了敏感性分析。(3)建立了外区为非牛顿幂律流体,考虑热损失、井筒储集效应、表皮效应和附加压力降的非牛顿幂律流三区复合油藏的试井模型,分别在外边界条件为无穷大、圆形封闭和圆形定压的情况下进行求解,绘制了相应的样板曲线并进行了参数敏感性分析。(4)建立了外区为非牛顿幂律流体,考虑井筒储集效应、表皮效应和附加压力降的非牛顿幂律流两区双孔介质复合油藏的试井模型,分别在外边界条件为无穷大、圆形封闭和圆形定压的情况下进行求解,绘制了相应的样板曲线并进行了敏感性分析。(5)建立了外区考虑启动压力梯度,井筒储集效应和表皮效应两区复合油藏的试井模型,分别在外边界条件为无穷大、圆形封闭和圆形定压的情况下进行求解,绘制了相应的样板曲线并进行了参数敏感性分析。(6)建立以上复合油藏定压条件下的产量递减变化的数学模型,作了相关参数对此类油藏产量递减曲线的敏感性分析。更多还原

【Abstract】 In company with our country oilfield entering the medium and late stage of recovery, the continual requirement of energy enlarging and oil and gas exploration impenetrating, it is more and more important to explore the unconventional oil-gas reservoir. Because of its huge reserves, heavy oil has significant practical significance to improve our country’s energy structure and remit the petroleum supply and demand’s pressure. Different from the conventional oil reservoir, the rheological characteristics of the heavy oil belongs to the kind of non-Newtonian fluid because it contains high molecular polymer, such as gum, pitch, wax etc, whereas assume the seeping characteristics of non-Newtonian which cause heavy oil’s exploitation more difficult than the conventional method. At present, it is widely adopted the thermodynamic method exploitation. Transient testing of heavy oil reservoir is a kind of extensively used method for obtaining formation characteristics, it is a important method to guide and monitor heavy oil recovery. At present this kind of research is merely based on general Newtonian fluid composite model. Owing to the seeping discipline’s complexity of heavy oil reservoir fluid, it causes prodigious deviation by adopting well testing method of conventional Newtonian fluid and the practical application also has the very big limitation. Therefore it is insignificant to develop the transient well test analysis theory and the explanation method of heavy oil thermal recovery, To establish the adaptive well test model and consummate analytical method for seeking the heavy oil reservoir’s natural parameter and offering technical support for productive capacity evaluation.This article is based on the widespread investigation and study and the earnest analysis of the domestic and foreign non-Newton well test literature. It accumulates in the research results of the predecessor and points to the steam-stimulated well’s problem of thermal recovery’s well testing, and then carrys out systemic research. It derives in detail and establishes the well test interpretation model from microscopic mechanism of seeping acquirement, and finds out the correspondence model’s solution and figures out the corresponding type curves. At the same time, it gets the flowing rate dynamic law analyses at the condition of bottom hole pressure for steam soak well.The main works mentioned in the article are: (1) to carry out certain research to Newtonian seeping mechanism and rheological property and infer the transfusion partial differential equation of the non-Newton heavy oil in the porous medium detailedly. (2) to establish well test model of two-zone composite reservoir that considering non-newtonian power-law fluid in outer region, the loss of heat, wellbore storage coefficient, skin effect and additional pressure fall, solve on occasions of the outer boundary is infinity, roundness enclosed and roundness constant pressure. figure out the corresponding type curves and carry out sensibility analysis.(3) to establish well test model of three-zone composite reservoir that considering non-newtonian power-law fluid in outer region, the loss of heat, wellbore storage coefficient, skin effect and additional pressure fall, solve on occasions of the outer boundary is infinity, roundness enclosed and roundness constant pressure. figure out the corresponding type curves and carry out sensibility analysis.(4) to establish well test model of two-zone double porosity media composite reservoir that considering non-newtonian power-law fluid in outer region ,the loss of heat, wellbore storage coefficient, skin effect and additional pressure fall, solve on occasions of the outer boundary is infinity, roundness enclosed and roundness constant pressure. figure out the corresponding type curves and carry out sensibility analysis.(5) to establish the well test model of two-zone composite reservoir that outer region is fulled with the fluid with starting pressure gradient considering the loss of heat, wellbore storage coefficient, skin effect and additional pressure fall, solve on occasions of the out boundary is infinity, roundness enclosed and roundness constant pressure. figure out the corresponding type curves and carry out sensibility analysis. (6) to establish above composite reservoir’s mathematical models of production decline at the condition of constant wellbore pressure,get sensibility analysis of relevant parameters to pool production rate’s decline curve.更多还原