Analysis of Plunger Lift Applications in the Marcellus Shale

Abstract

Abstract Field testing was performed on plunger lift systems in horizontal Marcellus shale wells. Plunger lift software from Echometer Company, Total Well Management, or TWM was used on certain wells to monitor acoustic trace, casing pressure, and tubing pressure throughout the plunger cycle. The plunger lift testing program addresses the challenges presented in shifting from vertical to horizontal well plunger lifting. The plunger lift testing addresses the feasibility of running plunger lift on wells with X and XN-profiles. These nipples are used to provide safe snubbing operations. The most valuable insight from the testing involves the possibility of running plunger lift to deviation angles of 70° and greater. The results of the plunger lift testing yielded several conclusions. An important result was that all plungers successfully passed through the X-profile, contrary to industry doubt. Another conclusion was that all plungers fell down to their bottom deviation angle with the deepest falling of 70°. Testing also showed the importance of performing TWM investigations on every plunger lift well to optimize plunger cycles. The most notable result was the phenomenon that plungers fell faster below kickoff point. This phenomenon suggests the possibility of plungers travelling to 90°. The observed trends of 53 TWM traces suggest that current plungers in horizontal Marcellus shale wells can theoretically reach a final deviation angle of 74°. Plunger lift systems have been used across the United States for decades to unload small amounts of liquid (water, oil, and/or condensate) as gas rates fall below the minimum critical rate to continuously unload fluids. The Marcellus shale is a vital asset to natural gas production in the United States. Development has transitioned from a vertical well science program to a proven horizontal well development program. Plunger lift has become common among some operators in the Marcellus shale for wells which have fallen below their critical gas rate. Our plunger lift program shows promise to maintain production after wells reach unstable flow up the tubing. Marcellus shale production can potentially benefit significantly if plungers eventually reach deviation angles of 90° since it will allow for production of fluid left in the horizontal lateral.