低渗透油田强化注水压力界限研究

低渗透油藏开发的难点就是注水不足，地层能量得不到有效补充，油井产量下降迅速。提高注水压力是解决此问题的最直接的办法，但不可能无限制地提高注水压力，还应该充分考虑地层、套管、地面设备的承受能力，因此有必要开展强化注水压力界限的研究。本文针对低渗透油田的地质特点，提出了合理注水压力的确定原则；依据材料力学理论，建立了套管承压能力计算数学模型，结合压裂施工参数，研究了油层破裂压力的计算方法，针对朝阳沟油田某区块的具体情况，确定了强化注水压力界限。

Pressure Limit of Enhanced Water Injection in Low Permeability Oilfield

During the developing of low permeability reservoir, it is difficult to inject water to meet the requirement, and that will result in no effective energy supplement to reservoir, and the production rate of oil well declining rapidly. The most direct way to solve the above problem is to increase water injection pressure. But it is impossible to increase water injection pressure without limit, the bearing capacities of formation, casing and surface equipments should be take into account. So, it is necessary to study the pressure limit of enhanced injection water. In this paper, the principle used to calculate reasonable water injection pressure is proposed according to the geological characteristics of low permeability reservoir. Based on the theory of mechanics of materials, a mathematical model for casing bearing capacity is established, and a method to calculate fracture pressure based on fracturing parameters is put forward. Then, the pressure limit of enhanced water injection of Chaoyanggou Oilfiled is presented.