无固相弱凝胶射孔液在渤海油田大位移井完井中的应用

Application of Non-solid-phase Weak Gel Perforating Fluid in the Completion of Large Displacement Wells in Bohai Oilfield

为了减少渤海油田完井作业过程中完井液的漏失,缩短返排时间,保障渤海油田大斜度、大位移井作业安全,降低压力亏空地层射孔作业卡枪的风险,此文分析了封堵机理及其特点,研发了无固相弱凝胶射孔液体系,并通过室内实验评价其剪切稀释、触变、封堵、抗温、抑制和返排等性能。实验表明,该体系既可通过形成弱凝胶封堵射孔产生的射孔孔眼,阻止完井液漏失,减少对地层的污染;同时也可提高压力亏空地层的地层承压能力,能有效悬浮地层出砂,防止射孔枪卡钻,还具有易返排的特性。该体系在渤海油田大斜度、大位移井的成功应用,有效满足了大斜度、大位移井射孔作业的需求。应用表明,该体系能大幅减少亏空地层作业过程中完井液的漏失量,缩短油井的返排时间,储层保护效果明显,具有很强的推广意义。

Through the analysis of plugging mechanism and characteristics,a solid free weak gel perforating fluid system was developed to reduce the leakage of completion fluid during well completion operations in Bohai Oilfield,shorten the backflow time,ensure the safety of high angle and large displacement well operations in Bohai Oilfield,and reduce the risk of gun jamming during pressure deficient formation perforation operations.Its shear dilution,thixotropy,plugging,temperature resistance,inhibition and flowback properties were evaluated through laboratory experiments.The experiment shows that this system cannot only prevent the completion fluid leakage and reduce the formation pollution by forming a weak gel to plug the perforation hole generated by perforation,but also improve the formation pressure bearing capacity of the pressure deficit formation,effectively suspend the formation sand production,prevent the perforation gun from sticking,and have the characteristics of easy flowback.The successful application of this system in high angle and high displacement wells in Bohai Oilfield effectively meets the requirements of perforation operations in high angle and high displacement wells.The application shows that this system can significantly reduce the leakage of completion fluid during the operation of depleted formations,shorten the backflow time of oil wells,and achieve significant reservoir protection effects.It has strong promotional significance.