ESP Conveyance Modelling in Higher DLS Wells

Abstract

Abstract With increasing numbers of unconventional horizontal wells on single pads and the desire to get deeper unconventional wells drilled to TD as economically as possible, higher well deviations and Dogleg Severities (DLSs) have posed challenges for Electrical Submersible Pump (ESP) conveyance. These challenges have led to situations where high bending stress during ESP conveyance has led to early ESP failure. To mitigate the potential for high bending stress during ESP conveyance, there has been: A renewed focus on drilling intermediate hole sections with low DLS, andWorkflow changes to obtain and analyze gyro surveys on wells following handover from Drilling before perf & frac operations. Summarized in the paper is a series of short run ESP failures in the Permian Basin that led to these new workflows for A/L selection and ESP conveyance planning. The study was initiated with a review of ESP teardown reports which revealed that most failures in the study area were not linked to high ESP bending stress during conveyance, but rather to Iron Sulfide (FeS) scaling within the ESPs. Nonetheless, Software was used to analyze and quantify ESP bending stress during conveyance for historical and future wells,A FeS scale inhibitor trial was initiated by adding chemical to the frac stages for some future ESP candidate wells, andApproximately 30 high resolution (1-ft) gyro surveys were collected in 5 ½" and 7" casing and processed at 1’, 15’, 25’ and 100’ intervals. Various metrics were calculated using the data, including wellbore DLS and Effective Rigid Pass-Through Diameter to highlight the advantage of gyros over traditional low resolution MWD surveys in wells where ESPs are planned.