高温高压深井射孔压力脉动及管柱动力响应机理研究

According to qualitative analysis, failures such as buckled and yielded tubing strings, broken mandrels of parkers, blocked down hole tools, are mainly caused by excessive pulse of pressure and releted dynamic loads due to jet perforating in high pressure and high temperature wells. As a special under water explosion project, study of pulsating pressure and tubing string dynamic response during jet perforating down oil wells is also a special fluid-structure interaction subject,considering the interaction between fastly moved fluid with large deformation and tubing, casing under the constraint by well hole which could be taken as narrow and long boundary. Based on accurate calculation of explosion parameters, differential equations of perforating pressure may be established by coupling models of ZND and drift flux model for multi-phase flow. Then, Smoothed Particle Hydrodynamics(SPH) will be used to analyze the differential equations to get pulsating rules of perforating pressure. Also, method coupled with SPH-LFDM（Lagrange Finite Difference Method）will be initiatively applied to analyze the interaction of perforation fluid and casing. At the same time, to examine the response of tubing string stimulated by perforating pressure, SPH revised by Large Deformation Elastoplastic Collision（SPH-LDEC）will be used to dispose the complexity due to constraints of narrow down hole and turbulence of perforation liquid. Stresses in tubing string exerted and stimulated by perforating pressure will be analyzed by transient dynamics. So, the safety of tubing strings and perforating works could be checked. To validate calculations and revise methods used and initiated, in-situ experiments will be conducted with down hole meters creatively made by the applicants. Besides, the coupled methd SPH-LFDM,SPH-LDEC initiatively used and practiced may work as new approaches for under water explosion study.

由于射孔压力脉动与管柱振动，高温高压深井射孔常发生管柱塑性弯曲、封隔器中心管断裂等事故。作为特殊的水下爆炸课题，射孔压力脉动与管柱振动研究需解决狭长边界下高速、大变形射孔液与套管、管柱的流固耦合问题。本项目在准确计算射孔爆轰参数的基础上，用多相流漂移通量和ZND耦合模型建立压力脉动方程并用SPH法求解，揭示射孔压力脉动规律；创新应用SPH-LFDM光滑粒子流体动力学与拉格朗日有限差分耦合算法，解决射孔液与套管的流固耦合分析问题；应用大变形弹塑性碰撞理论修正SPH法（SPH-LDEC），分析射孔段管柱与射孔液的流固耦合及其动力响应机理；通过井下实测验证射孔脉动压力及管柱冲击理论分析结果；运用有限元瞬态响应方法分析脉动压力及冲击载荷作用下管柱的强度安全性，为高温高压深井射孔参数设计、管柱组合及安全作业提供依据。SPH-LFDM、SPH-LDEC耦合算法还可为水下爆炸研究提供新思路。

针对高温高压井射孔常发生管柱塑性弯曲、封隔器中心管断裂等事故，应用炸药学、爆炸力学和冲击动力学理论，准确分析爆轰参数，建立射孔压力脉动方程，用SPH方法求解，揭示了射孔压力脉动规律；通过解决狭长边界下高速、大变形射孔液与套管、管柱流固耦合问题，搞清了射孔液与管柱流固耦合及其动力响应机理；形成了冲击载荷下管柱的强度安全性分析方法；在国内首次进行了射孔爆轰压力脉动和管柱振动实测；射孔通道建立后，考虑流体流动引起射孔套管外载变化及其力学行为改变，据此建立了流体流动影响射孔套管强度安全的分析方法；建立了射孔爆轰对封隔器密封和定位性能影响的分析方法。为高温高压深井射孔参数设计、管柱组合及安全作业提供了依据。.以项目取得的研究成果为基础，在冀东油田开展了“射孔完善程度与井筒安全性分析”项目，形成了“冀东油田射孔综合优化设计软件”，进行了50余口井的射孔优化设计，应用至今。与西部钻探测井公司合作，开展了“新疆油田油气藏射孔机理研究及设计平台开发”为代表的射孔系列项目，依托其对外技术服务，在新疆油田、塔里木油田、西南油气田等单位得到应用。为塔里木油田、新疆油田、大庆油田、冀东油田、华北油田、大港油田、青海油田、西南油气田一百余口高温高压井试油与完井射孔作业提供了技术指导，确保了射孔及后续改造作业的安全。据五家应用企业不完全统计，通过本项目成果的应用，减少了完井与试油管材消耗，减少了修井处理事故的时间，进而减少了修井费用和产量损失，产生直接或间接经济效益12613万元。.发表论文16篇，其中，SCI/EI收录论文6篇，期刊论文10篇；授权发明专利2项、实用新型专利10项；取得软件著作权2项；获得省部级一等奖1项，二等奖3项。培养在读博士研究生2人、毕业硕士6人、在读硕士研究生2人。通过项目研究，提升了项目组年轻教师的科研能力、拓宽了研究思路，曹银萍和王治国晋升副教授，曹银萍获评校级青年骨干教师。