Developing a Platform Strategy and Predicting Torque Losses for Modeled Directional Wells in the Amauligak Field of the Beaufort Sea, Canada

Abstract

Abstract Nine exploration wells drilled by Gulf Canada Resources Ltd. have defined the Amauligak Field in the Beaufort Sea, Canada as being roughly 3 by 12 kilometers in size. An oblong offshore field like this normally would be developed with several platforms. Due to the expense of development structures in the Arctic, it is worthwhile to evaluate drainage of the field from a single platform with extended reach wells. Previous experience gained from the directional wells in the field highlighted problems with excessive drill string torque. This led to concern that the planned extended reach wells would be beyond normal driliability. An accurate prediction of torque losses for these planned wells was necessary to prove the feasibility of the single platform concept. This paper demonstrates a technique used to predict the total torque losses expected in drilling directional wells. It is based on an analysis of expected drill string side-forces using field derived friction data which has been documented in previous papers (1,3,4). To successfully predict losses on future wells, a simulation of possible corrections to the directional plan, sidetracks and dog-leg severity must be added to the original directional plan. The method described here, simulates survey data with variations on inclination and azimuth that are matched to the corrections and dog-leg severity found in the nearby wells., These effects can increase torque losses by up to 70% above the "ideal" plan. A 50 well scenario was developed for the field from a 60 slot platform. Ideal directional plans were made and then altered to minimize collision possibilities. A design case directional path with corrections and dogleg severity was simulated, applied to the ideal plan and associated torque losses predicted. The value of these losses were used to size drill string components and top drive equipment. The results of this study demonstrated the feasibility of using a single platform to develop the field.