透镜体低渗透岩性油藏合理井网井距研究

透镜体低渗透岩性油藏具有砂体分布零散、非均质性强等特点，开发过程中核部水淹严重，扇缘部水驱效果较差。为此，基于油藏工程方法与理论推导，确立了环形井网环距及采油井井距的计算方法并绘制了计算图版，同时，结合数值模拟方法，对透镜体低渗透岩性油藏有效开发的合理井网井距进行了研究。结果表明：基于相控剩余油条件下的核注翼采井网模式，可有效缓解正方形面积注水井网形式注水憋压的难题，进而降低注水难度，提高水驱效率；与正对井网相比，采用注采井数比为1∶2的核注翼采交错环形井网时，油水井流线分布较均匀，开发效果较好；对于3注6采与4注8采的环形井网，当环距为200 m时，最优采油井井距分别为300 m和250 m。该研究成果为透镜体低渗透岩性油藏的持续高效开发提供了理论基础和借鉴。

Reasonable pattern well spacing deployment of lens lithologic reservoirs with low permeability

The lens lithologic reservoir with low permeability is characterized by scattered distribution and strong heterogeneity of sand body. During the process of development,the core is seriously flooded and the water flooding effect in fan edge is poor. Therefore,based on the method and theory of reservoir engineering,the calculation methods of ring spacing of annular wells and well spacing of oil well were established,and the calculation chart was drawn. At the same time, the rational pattern well spacing for lens lithologic reservoir with low permeability was studied by numerical simulation method. The results show that the well pattern of core injection wing production based on the phase control residual oil can effectively alleviate the problem of water injection pressure in the form of square water injection well pattern,and then reduce the difficulty of water injection and improve the efficiency of water flooding. Compared with the positive well pattern,when the injection to producing well ratio is 1:2 in the cross annular well pattern of core injection wing production,the streamline distribution of the oil and water wells is more uniform,and the development effect is better. For the annular well pattern with the injection and production wells number of 3 and 6 or 4 and 8,when the ring distance is 200 m,the optimum well spacing of production wells is 300 m and 250 m,respectively. This study can provide a theoretical basis and reference for continuous and efficient development of lens lithologic reservoirs with low permeability.