Evaluating Tubing Completions using High-Resolution Gyro Logs to Improve Rod Pumping Systems Run Life

Abstract

Abstract In some unconventional plays, highlights typically installed following stimulation activities. Production tubulars are designed to flow the well during natural flow period and later accommodate an artificial lift system without a major intervention. To achieve this objective, while maintaining full pressure containment without using high density killing fluids to mitigate induced formation damage and lower costs the ability to manipulate the tubing is limited and with it, the required tubing tension for rod lift operation cannot be obtained with traditional mechanical anchors. This paper describes a systematic process to evaluate the tubing tortuosity using high resolution gyro logs to improve rod pumping operation in wells with different types of anchoring mechanism: Tubing packers, hydraulically set anchors and dynamic set anchors. With the use of snubbing unit, it is required to contain well pressure during the entire tubing deployment without killing the well, the use of traditional mechanical tubing anchor is not possible. To avoid tubing movement during the rod pumping phase of the well, the tubing string considers hydraulically set tubing anchors estimating that the final tension is primarily based on differential pressures calculation with assumed friction factors. As downhole flowing conditions change over time, inspection of tubing was performed using high resolution gyro in a selected number of wells that were equipped with different types of tubing anchoring or packer mechanism to evaluate the trajectory and optimize the rod string design. Initial result shows higher tubing buckling than what was initially expected and additional rod-tubing friction during rod lift operation, this additional friction encountered mislead the surface and downhole cards calculation and mask abnormalities in downhole pump behavior. The result of this analysis also highlights that the certain tubing designs are not adequate to achieve the objective of accommodating natural flow and rod pumping system with the same initial tubing installation. Factors such as wellbore trajectory, frictions and temperature play a more significant role in determining final tension profile in the tubing, also dynamic anchoring system in lieu of traditional hydraulic anchor has potential to achieve the objectives, keeping the capability to deploy a suitable tubing design for rod pump at early stage while maintaining full pressure containment. The novelty of this methodology lies on the analysis of the tubing trajectory at different pressure conditions utilizing high resolution gyro logs and typical data analysis tools to achieve a better representation of the tubing condition over time in order to support the rod lift design and improve future equipment run life