Evaluation of the influence of reservoir fluid on the occurrence of sticking of drill strings and casing strings under the influence of differential pressure

Abstract

In the work, a dependence was obtained, analyzing which it is easy to see that the dimensionless parameter of sticking hazard depends very significantly on the permeability of the reservoir and increases in proportion to the increase in pressure drop, which is fully confirmed by the results of numerous experimental studies of sticking under the action of pressure drop. At the same time, one of the main, but previously not taken into account, factors that contribute to the occurrence of sticking in drilling wells is the viscosity of the formation fluid, as it decreases, the dimensionless sticking hazard parameter (i.e., the possible sticking force) in the interval of occurrence of a given permeable formation increases sharply. Indeed, the experience of drilling operations in various regions indicates that when drilling wells in gas fields, the frequency and severity of sticking is much higher than when drilling wells in oil fields, this requires special consideration in the process of drilling wells in gas fields. Keywords: sticking; drilling and casing strings; differential pressure; filter cake; viscosity; formation fluid.