A Proposed Method for Planning the Best Initial Response to Kicks Taken During Managed-Pressure-Drilling Operations

Abstract

Summary An industry-supported research project has investigated well-control methods for managed-pressure drilling (MPD) using the constant-bottomhole-pressure (CBHP) method. This paper proposes a method for planning the best initial response to be used when a kick occurs during CBHP MPD on the basis of conclusions from the research. That research (Davoudi et al. 2010) concluded that the three most widely applicable initial responses to kicks during MPD were increasing casing pressure until flow out equals flow in, shutting the well in, and using an adaptation of an MPD-pump shutdown schedule to detect and shut in a low-rate kick. Increasing pump rate until flow out equals flow in was concluded to have limited, but potentially still important, applications. The proposed method uses a decision tree during the planning phase of a well to select the best kick response to be used for each hole interval for inclusion in the drilling program. This selection is based on the desired tolerance to kicks, equipment being used, well geometry, and conclusiveness of the kick warning signs. The equations necessary to calculate decision parameters, example calculations for an application of the decision tree, and comparison of simulation results to application of the decision tree are included. The decision tree indicates the response that maximizes kick tolerance within the well design, gives a basis for revising equipment or well design to maximize kick tolerance, and supports calculation of the expected kick-tolerance advantage of the increasing-casing-pressure response vs. a shut-in response.