渤海湾疏松砂岩储层微观特征及开发实践

Microscopic Characteristics and Development Practice of Unconsolidated Sandstone Reservoir in Bohai Bay

渤海PL油田属于易堵疏松砂岩油藏,具有含油井段长、小层数量多、沉积类型复杂多样等特点。由于早期的水平井试验井失利,长期以来水平井被认为不适合在渤海PL油田应用。基于渤海PL油田微观储层特征,采用渗流理论、数值模拟与矿场实践相结合的方式,研究得到了易堵疏松砂岩水平井评价技术和厚薄间互多层油藏联合井网分类开发技术。结果表明,在近井地带,水平井的圆柱与半球结合体渗流区域的单位面积流速远小于定向井圆柱体渗流区域的单位面积流速,矿场实践证实了水平井在易堵疏松砂岩储层中对抗速敏现象更具优势。对多层厚薄间互油藏联合井网中的定向井与水平井的干扰进行对比,证明在中高含水期,地层能量是联合井网中井间干扰的主控因素。

As a loose sandstone reservoir,PL oilfield has been characterized by its strong velocity sensitivity,long oil-bearing intervals,multiple oil-bearing sequences and complicated sedimentary types.Due to the previous failures of earlier application,horizontal well has always been considered to be not suitable for PL oilfield.Based on the micro reservoir characteristics of PL oilfield in Bohai Sea,the evaluation technology of horizontal well in loose sandstone and the classified development technology of combined well pattern in thick thin multi-layer reservoir are studied by means of seepage theory,numerical simulation and field practice.The results indicates that,the unit area velocity of the cylinder hemispherical combination seepage area of the horizontal well is far less than that of the cylinder seepage area of the directional well in the near well zone.The field test data proves that horizontal wells have more advantages in resisting velocity sensitivity in unconsolidated sandstone reservoirs.The interference between directional well and horizontal well in the combined well pattern of multi-layer thick thin reservoir is compared.It is proved that whether the formation energy is sufficient or not is the main controlling factor of inter well interference in the combined well pattern during the period of middle and high water content.