Managed-Pressure Drilling: Kick Detection and Well Control

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 124664, ’Roles of Managed-Pressure-Drilling Technique in Kick Detection and Well control - The Beginning of the New Conventional Drilling Way,’ by Paco Vieira, SPE, Maurizio Arnone, SPE, and Fabian Torres, Weatherford International, and Fernando Barragan, AGR Group, originally prepared for the 2009 SPE/IADC Middle East Drilling Technology Conference and Exhibition, Manama, Bahrain, 26-28 October. The paper has not been peer reviewed. In times when the oil industry is looking for drilling technologies to optimize field development, managed-pressure drilling (MPD) has become an attractive technology, offering considerable benefits. MPD is an optimized drilling process used to control the annular pressure profile more precisely throughout the wellbore. The annular pressure profile is controlled from surface so that the bottomhole circulating pressure (BHCP) is balanced with the pore pressure at all times. Introduction Controlled-pressure-drilling (CPD) technology has enabled the commercial development of numerous oil and gas reservoirs worldwide that otherwise would not have been exploited because of technical and/or economic limitations. CPD has become possible only as a result of the integration of many developing technologies that facilitate directional control of the well trajectory, control of the BHCP, and the safe handling of drilling fluids and drill cuttings at surface. MPD is a drilling technology that uses a pressurizable fluid system and specialized equipment to control the wellbore pressure profile more precisely. Application of this technology optimizes the drilling process by decreasing nonproductive time and mitigating drilling hazards associated with pressure fluctuations that occur when conventional drilling techniques are used. Many drilling and wellbore-stability-related issues stem from the significant fluctuations in bottomhole pressure (BHP) that are inherent to conventional drilling practices. These fluctuations stem from the stopping and starting of circulation during drillstring connections in jointed-pipe operations; specifically, they result from a change in equivalent circulating density (ECD) that occurs when the pumps are turned on and off. MPD technology, and more specifically, constant BHP (CBHP) as a variation of MPD, is applicable to avoid changes in ECD by applying appropriate levels of surface backpressure, a technique that maintains a CBHP during the complete drilling operation. Additionally, CBHP enables safe application of conventional well-control procedures when unexpected high-pore-pressure formations are encountered. This requires that MPD systems play roles in kick detection and well control.