气顶边水油藏开发策略研究与实践

Study and practice of developing strategy on reservoirs with gas cap and edge water

气顶边水油藏在开发过程中容易引起气窜和水窜,造成不可挽回的储量损失。B区块具有一定的气顶规模和油环宽度,弱边水,根据这些特点,通过研究其储层的渗流特征,制定了气顶注水障+边外注水+内部点状注水的方法,指出了影响开发效果的主要因素。同时,配合注水,采取了一些油藏和工程方法,包括合理的生产压差,合理的流压界限,合理注采比以及避水、避气射孔。通过这些开发策略的制定,B区块的开发取得了良好的效果。区块含水和气油比保持相对稳定,各项指标均表现出良性开发的特征,为此类油藏的开发提供了借鉴。

Improper development of reservoirs with gas cap as well as edge water can usually lead to gas and water breakthrough, which could cause irreversible reserve costs. According to the characters in Block B, such as certain amount of gas cap, medium oil ring width and weak edge water, flow mechanism of reservoir was studied. Based on them, a strategy of mixing with water barrier flooding in gas cap, edge water flooding and inner scattered flooding was proposed, and then the main factors influencing developing effect were pointed out. Meanwhile, other reservoir and engineering methods were adopted to comply with the flooding, which include reasonable producing differential pressure, flowing pressure boundary, injection-production ratio, water and gas avoid perforation. With the development policy and measures implementation, considerably well developing results were achieved. Water cut and GOR remain stable, and all the development indexes show fine exploiting feature. It provides reliable theory and practice guide for this kind of reservoirs.