Analysis Of The Erosion Phenomena Of Downhole Completion Equipment

A major North Sea field was put on stream in the autumn of 1988. Since then, over 1.7 billion barrels of oil have been produced, reaching a peak of more than 500,000 BOPD. Today, an estimated 0.9 billion barrels of oil remain to be recovered from this field; however, production has fallen to less than 400,000 BOPD and the operator is facing tremendous challenges to increase production. New technologies, such as horizontal drilling, have helped increase production in this field. Three multilaterals have also been drilled to help offset falling production. This paper discusses horizontal oriented perforating in long horizontal sections designed to optimize production from the field. Drilling in a water depth of 109 m of water off the coast of Norway, the operator wanted to optimize production from a 2246-m horizontal well section by reducing the risk of future sand production and selecting the most effective perforation coverage. Minimizing debris and rig time were the other key objectives. Perforating in highly deviated or horizontal wells presents any service company with a serious technical challenge. Attempting to maintain wellbore and perforation tunnel stability by perforating in the direction of maximum stress compounds the complexity of the perforating job. Ensuring that orientation remains valid while navigating through severe doglegs requires detailed pre-job design planning supported by applicable research data. This paper explores some of the results and experiences encountered while performing an oriented perforating job in a 2246-m horizontal section of a North Sea well. A world record was set by perforating a total of 1496 m of the horizontal section in a single trip with orientation successfully verified. The latest advances in performing oriented perforating in horizontal wells and verifying the direction of the perforations are discussed. Additional discussion on the testing and research that preceded the job is presented. As demonstrated in this North Sea well, perforating with oriented charges in horizontal sections will play a key role in the future to assist operators increase and optimize production from declining fields. Currently, over 60 oriented perforating jobs in horizontal wells have been successfully performed all over the world.