Drag reducer extends coiled tubing uses for complex wells

摘要

A recently introduced ADFR fluid is enabling more economic operations in extended-reach wells. Achieving the benefits of coiled tubing (CT) operations in the extremities of today's extended-reach wells can be difficult and expensive. Overcoming the frictional forces - drag and torque - that are encountered as the CT is pushed into the well bore often requires the use of tractors: hydraulically operated devices that literally pull the CT into the well bore. The forces encountered can greatly reduce the amount of set-down and pickup force that can be applied to the bot-tomhole assembly (BHA) via the CT. They can prevent achieving the necessary horizontal reach with the CT. If the force that can be applied both in pushing and pulling the CT is significantly reduced, the ability to perform CT-based operations can be severely curtailed. Also, the additional drag and torque can shorten the life of the CT string, affecting both cost and reliability.