| Popis: |
Remedial Sand Control is a challenging operation that requires economic judgment especially in brownfields. The operation turns into a greater challenge when the well, that needs to have a damaged gravel pack screen repaired is a sub hydrostatic well. We carried out pioneering repair project that was simple and cost-effective with minimum logistics using thru-tubing sand control. This method adapts thru-tubing tool advantages of coiled tubing to convey and set a smaller sand screen in a damaged gravel pack bore. The operation started by cleaning out in the deviated wellbore, controlling the well from kicks and deploying a long sand screen string in open-well conditions. To use this technique, two main challenges had to be solved. First, a long sand screen string had to be deployed into the wellbore on a production platform without the assistance of the derrick or platform crane. We used a two-stage self-skidding jacking frame with a 4-ton hydraulic winch to deploy the screen string into the well. Each un-deployed component of the screen string was lifted up from the storage rack with an elevator and connected with the string in the wellbore above the Christmas tree by a hydraulic tong. The installed string was held above the Christmas tree by a pneumatic slip and bowl mechanism. Second, the method must control the well from unexpected kicks while the sand screen is being deployed. We used hydraulic hydraulic well control method, which involves spotting "damaged free" lost-circulation material (LCM) fluid along target intervals and topping up with kill fluid, we also prepared a mechanical solution as a back up during job execution. |
