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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.
In recent years, with the continuous exploitation and exploitation of oil, reservoirs are hard to pass the classical seepage mechanics theory and the traditional reservoir numerical simulation method in the research fields such as high pressure water injection and heavy oil thermal recovery, which involve the dramatic temperature changes. In order to obtain an effective and reasonable explanation, we must take into account the changes in temperature field, seepage field and stress field interactions, interactions, mutual changes, etc. Based on the stress-strain relationship of rock considering thermoelasticity, the law of motion of underground fluid, energy The law of conservation and the establishment of three coupled mathematical models of heavy oil reservoirs, including the oil-water two-phase seepage control equation, the rock deformation body control equation and the temperature field governing equation, and the full coupling algorithm is used to solve all coupling equations at the same time. The modeling process and method of three coupling rules are analyzed by software ADINA.The three coupling rules are studied by taking the case of depression 38 in Xiaowei Oilfield as an example.The results show that the closer the distance to the wellbore, the total displacement, temperature field, stress field and seepage field And the physical parameters of rocks will have obvious changes; the farther away from the wellbore, the less obvious change.The distance from the wellbore The more the layer temperature changes violently, and the farther the reservoir from the wellbore changes slowly. The temperature change around the wellbore presents the shape of inverted funnel. As the water injection continues, the funnel will gradually flatten. Finally, the temperature at each reservoir will be balanced At the same temperature level, the equilibrium state is reached.The model is more realistic to simulate the actual exploitation of the reservoir.