Research on the passability of pumping bridge plug tool string for horizontal wells

Abstract:

The combined operation technology of horizontal well pumping bridge plug perforation has been widely used in the development of unconventional oil and gas reservoirs such as shale gas， shale oil and tight oil. In this process， the toolstring with drillable bridge plug and multistage perforating gun is sent to the designated position by hydraulic pumping. Due to the complexity of wellbore trajectory and wellbore environment， the pumping blocked and stuck occasionally occurs. According to the structural characteristics of the pumping bridge plug tool string for horizontal wells， this paper simplifies the tool string， the rigid geometric relationship between the tool string and the wellbore in the curved well section under a certain dogleg degree is analyzed， the method for determining the contact point between the pumping bridge plug tool string and the pipe wall is proposed， the stress bending characteristics in curved well sections are analysed， and the criteria for passability is established. According to the actual cases， the influencing factors including the well trajectory， the largest dogleg degree and the inner diameter of the pipe wall are analyzed， and the optimized scheme of pumping process parameters is given to reduce the occurrence of downhole accidents.

Key words:unconventional oil and gas;reservoir development;horizontal well;bridge plug;tool string;passability