洼38块特稠油油藏流-固-热三场耦合规律研究

The Study On Flow-solid-temperature Three Field Coupling Law of Extra-Heavy Oil Reservoir Wa-38 Block

近年来,随着石油的不断开发开采,在研究高压注水,稠油热采等涉及到温度剧烈变化的研究领域中,油藏工作者难以通过经典的渗流力学理论和传统的油藏数值模拟方法得到有效、合理的解释,必须考虑到温度场、渗流场、应力场三场相互影响、相互作用、相互变化等相关变化因素.基于考虑热弹性的岩石应力一应变关系、地下流体运动定律、能量守恒定律,建立包括油水两相渗流控制方程、岩石变形体控制方程、温度场控制方程的稠油油藏三场耦合数学模型,运用全耦合算法实现同时求解所有耦合方程组,研究了应用有限元分析软件ADINA进行三场耦合规律的建模过程与方法.以小洼油田洼38块为例研究三场耦合规律.结果表明:距离井筒越近,其总位移、温度场、应力场、渗流场及岩石物性参数越会产生明显的变化;距离井筒越远,其变化越不明显.距离井筒越近的储层温度变化越剧烈,而距离井筒越远的储层温度变化越缓;井筒周围的温度变化呈现倒置漏斗形状,随着注水的不断进行,漏斗会逐渐平缓;最后储层各点的温度会平衡在同一温度水平线上,达到平衡状态.模型较为真实的模拟油藏实际开采情况.

Recent years, with the continuous exploitation and development of oil, in some research areas, such as hermal production of heavy oil, in which temperature changes severely, it is hard to reservoir workers to find out effective and reasonable explanation through classical mechanics theory of fluid flow and traditional numerical simulation method of reservoir. Because we must consider some factors such as temperature, seepage and pressure field mu- tual influence, interaction and change. Based on the consideration of the relationship between thermoelastic rock stress and strain, the law of underground fluid motion and conservation of energy, and establish the heavy oil reservoir coupling mathematical three field mode with which include equations of oil-water two-phase flow, equations of rock deformation body and equations of temperature field, solved All coupled equations simultaneously by using full cou- pling algorithm, studied the process and method Of three-field coupling modeling by using ADINA which is a software for finite element analysis. Take Wa-38 Block of Xiaowa oilfield for example, with the study the three field Coupling law, the results showed that：The closer from the wellhole, the more significant changes in total displacement, temperature field, stress field and seepage field; The farther away from the weUhole, the change is less obvious. The reser- voir closer from wellhole, the temperature changes more intense, and the farther away from it, temperature changes slowly; The temperature variation around the wellhole presents an inverted funnel shape, with the water injection constantly, the funnel will gradually change to fiat; Finally, the temperature of each point of reservoir will be balance at the same horizontal line. This model simulate the actual conditions of reservoir mining really.