东河油田注气出砂机理及实验

Mechanism and experimental study of gas injection and sand production in Donghe oilfield

沈建新,黄锟,钟婷,王杰祥,童世俊,王亮亮,苏洲,王鹏

中国石油塔里木油田分公司油气工程研究院，新疆 库尔勒 841000 中国石油大学（华东）石油工程学院，山东 青岛 266580

Research Institute of Oil and Gas Engineering, Tarim Oilfield Company, Kuerl 841000, China School of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China

塔里木东河油田埋藏深，温度高，压力高，渗透率低，经注水开发后，现转入注气开发。随着注气开发时间的增加，出砂问题严重、油井免修期短、长时间砂埋油层对油井正常生产造成了严重的影响。东河油田发育广海型海滩沉积，非均质性强，胶结程度低，具备出砂内因。结合生产日报和井下作业日志等现场资料，可知生产压差、作业频率和产液流速等是油田出砂的主要生产因素。通过粒度分析和铸体薄片等岩心物性实验，分析了岩心粒度分布、主要成分、孔喉结构及胶结情况等，验证了粉细砂岩及弱胶结容易造成出砂；速敏实验结果显示，随着流速的增大，渗透率损害程度显著增强，也导致油层容易出砂；注气出砂机理实验结果表明，高流量的气液混合物紊流进一步加大了油层出砂的可能性。文中用理论与实验阐明了东河油田出砂的机理，为油田下步防砂工作提供了有力的依据。

The Donghe Oilfield in Tarim basin has deep burial, high temperature, high pressure and low permeability. After water injection development, it is now transferred to gas injection development. With the growth of gas injection development time, the problem of sand production has become more and more serious, the maintenance-free period of oil well production is short, and the long-term sand-buried oil layer has severely affected the normal production of oil wells. Donghe Oilfield developed wide-sea beach deposit with strong heterogeneity, low degree of cementation, and internal causes of sand production. Combined with on-site production data such as daily production reports and downhole operation logs, the main external causes of sand production in the oilfield are analyzed, including production pressure difference, operation frequency, and liquid production flow rate. Through particle size analysis and experiments of casting thin slices and other core physical property, the core particle size distribution, main components, pore throat structure and cementation are analyzed, and it is verified that silt sandstone and weak cementation are easy to cause sand production. The results of speed-sensitive test show that with the increase of flow velocity, the degree of permeability damage increases significantly, which makes the oil layer easy to produce sand. The experimental results of the gas injection and sand production mechanism show that the turbulent flow of high-flow gas-liquid mixture further increases the possibility of sand production in the oil layer. The combination of theory and experiment clarified the mechanism of sand production in Donghe Oilfield, and provided a strong basis for the next step of sand control in the oilfield.

10.6056/dkyqt202106024