桩西油田桩74块注浅层水可行性研究

A Study on Applicability of Shallow Formation Water for Flooding Reservoir at Block Z74 of Zhuangxi Oil Field

考察了桩 74 14 14井浅层水和桩西联合站处理后采油污水用作超低渗透率 (平均 6 .1× 10 - 3μm)的桩 74块油藏的可行性。测定了不同比例的浅层水、采油污水与油藏地层水混合后 ,各种矿化离子浓度的变化 ,由此确定浅层水、采油污水与油藏地层水在常温常压下是完全配伍的 ,在模拟油藏条件下 (130℃ ,15MPa)是不配伍的 ,会产生碳酸钙垢。由理论预测知 ,浅层水和油藏地层水混合后产生的碳酸钙垢量很少 ,而采油污水和油藏地层水在高混合比例下产生的碳酸钙垢量较多 ,且有碳酸锶垢生成。对浅层水和采油污水作为注入水的水质进行了现场检测 ,结果表明悬浮固体和粒径中值超标 ,经精细过滤后可降至标准值以下。作者建议采用浅层水并提出了继续研究的问题。表 6参 1。

The shallow formation water (SFW) from well Z74 14 14 and the purified produced water (PPW) from Zhuangxi oil gathering/water treating plant are investigated as flooding water for use in reservoir Z74 of very low permeability (6.1×10 -3 μm 2 in average). The determinations of inorganic ions show that the mixture of SFW and of PPW with the reservoir formation water (RFW) in all proportions is compatible at room temperature under atmospheric pressure and is incompatible and creates CaCO 3 scale at simulation reservoir conditions (130℃,15 MPa). By using theoretical prediction methods it is recognized that the CaCO 3 scale amount formed will be little for SFW+RFW and more for the PPW+RFW of high PPW volume fraction with SrCO 3 scale formed in the later case. The quality of SFW and PPW is determined at site and the data obtained show rather high suspended solids and particle size median which can be lowered to below the required values by additional fine filtration. For flooding reservoir Z74 the author prefers SFW to PPW and suggests some comments on further investigation.