Parameter control methods for the pumping toolstring composed of perforating gun and fracturing plug in a horizontal well

Abstract

According to the technological characteristics of the combination perforation and multistage fracturing using drillable bridging plugs, both the hydrodynamics model of wireline sealing system and the mechanical model of toolstring running in the hole were developed. In these models, the equations governing the sealing pressure of grease injection, structure parameters of toostring and pump rate were established. Based on the presented models, the parameter control methods of pumping and their primary influence factors were investigated through case study. For a development well in low-permeability reservoir, the control methods and the reasonable ranges of grease injection sealing pressure, minimum weight and maximum length of toolstring and pump rate were defined using the control equations. The effects of wellhead pressure, hole configuration and running velocity of wireline on parameter controlling were also analyzed. The results show that, with increasing wellhead pressure, the grease injection rate should be increased to improve sealing pressure, and the minimum weight of toolstring should also increase. Increasing the overall angle change rate could lead to a decrease of the maximum allowable length of the toolstring. The pump rate should be adjusted according to the running velocity of wireline. Key words: horizontal well, multistage fracturing, wireline conveyed perforation, toolstring, pump parameter, drillable bridging plug, low-permeability reservoir