80 MPa保压取心工具的研制与应用

Development and Application of 80 MPa In-situ Pressure-Preserved Coring Tool

为充分认识深井、高温井区块原始地层条件下岩心的油气组分物性和结构构造,真实评价该区块油气储量,文章以现有保压取心技术为基础,通过优化设计、技术创新成功研制出80 MPa保压取心技术。该技术设计的氟素橡胶密封件可以长时工作在井下150℃高温环境中并保持良好的橡胶性能,满足高温环境中静、动高压差密封;球端活塞承高压金属密封、承低压胶环的双密封设计;优选7075型硬质铝合金内筒,优化设计工具壁厚及增强丝扣强度实现内筒总成承压差80 MPa;通过表面镀层及涂层处理应对井下长时间高温、高循环压耗的工作环境,提高保压取心工具安全性。现场应用表明,80 MPa保压取心技术可以满足深井、高温井保压取心的技术需求,对于深井、高温井地质勘探开发及储量评价具有重要意义。

In order to fully understand the physical properties and structural structure of oil and gas components of cores under original formation conditions in deep and high temperature well blocks and truly evaluate the oil and gas reserves in these blocks,80 MPa in-situ pressure-preserved coring tool was successfully developed based on the existing in-situ pressure-preserved coring technology through optimization design and technological innovation.The fluorine rubber seal designed by this technology can work under high downhole temperature of 150℃for a long time and maintain good rubber performance,realizing the static and dynamic high pressure differential seal in high temperature environment.Ball end piston adopts double seal design(mechanical seal for high pressure)and rubber seal for low pressure.The inner cylinder is made of 7075 aluminum alloy.The wall thickness of the design tool is optimized and the strength of the thread is enhanced to achieve a pressure difference of 80 MPa.Through the surface coating and coating treatment,this tool can be used for a long time in the working environment with high temperature and high circulating pressure loss,and its safety is also improved.The field application shows that the 80 MPa in-situ pressure-preserved coring technology can meet the technical requirements of deep-well and high-temperature well in-situ pressure-preserved coring,giving a great significance for their geological exploration and development and reserves evaluation.