水力喷砂射孔机理实验研究

EXPERIMENTAL STUDY ON MECHANISMS OF HYDRAULIC SAND BLASTING PERFORATION FOR IMPROVEMENT OF OIL PRODUCTION

根据材料冲蚀磨损理论和磨料射流切割原理 ,对利用水力喷砂射孔技术切割套管和近井地层岩石的机理及其影响因素进行了分析。在实验室条件下进行了水力喷砂射孔地面模拟实验 ,并在胜利油田现场进行了施工工艺设计和试验。实验结果表明 ,在压力为 2 3～ 2 4MPa的条件下 ,水力喷砂射孔能有效地穿透套管并在天然砂岩上射出直径 30mm以上、深达 780mm的孔眼 ,现场试验证实水力喷砂射孔油井增产效果明显。水力喷砂射孔增产的机理主要是解除近井地带污染 ,松弛密实圈 ,避免炮弹射孔的压实污染 ,增加地层渗透率并扩展油流通道。

On the basis of erosion wear theory of materials and the abrasive water jet cutting process, the mechanisms of both casing cutting and formation rock cutting with hydraulic sand blasting perforation of oil wells are discussed, and the influencing parameters are investigated. The preliminary experiments of hydraulic sand blasting perforation both in laboratory and on field are conducted. The simulation experiment in laboratory shows that the casing can be easily cut with the hydraulic sand blasting perforation. The sandstone can be perforated, and a hole with 30 mm in diameter and 780 mm in depth can be made on the sandstone at jetting pressure of 23～24 MPa. The field tests show the promising potential enhancement of oil production with the technique. The improvement of oil production with hydraulic sand blasting perforation is mainly resulted from the removement of the near well bore pollution, looseness of the compacted zone, increase of the formation permeability, which extends the passage way of oil flow.