Successful Coiled-Tubing-Based Sand Consolidation Treatment in Remote Wells in Challenging Offshore Environment: A Case Study

Abstract

Abstract CB/OS-2 field is located offshore the west coast of India. The wells are of shallow depth with sanding issues. Many wells are either shut in or beaned back to control drawdown and ensure sand-free production. This has resulted in wells flowing at much lower rates than their potential. Conventional coiled tubing (CT) jobs or jobs that use a catenary system are not feasible because of the tidal/current conditions and limited load capacity of platform crane. A platform-based CT sand consolidation operation using a modular and compact unit was conducted in two wells (XA 5 and XA 6). A 20-t modular crane was installed on the platform, and a detailed platform structural load analysis was carried out for spotting the CT unit and auxiliary equipment. Since no core samples were available from the field, sand consolidation tests were conducted on a bailed-out sand sample. A CT-conveyed inflatable packer was used to isolate the deeper section of the completion. The recipe was modified and customized to suit the logistical and fluid-handling constraints on the platform. After a sand-consolidation resin treatment, well XA-05 is now producing 1,200 BOPD, in contrast to the earlier, pretreatment 300 BOPD. Well XA-06, which was shut in due to sanding issues, is now producing 300 BOPD. The wells are stable, and periodic intervention has confirmed that there is no sand fill. Pressure surveys also indicated that there has been no skin after the treatment. Despite the many technical and logistical constraints, the sand consolidation jobs were successful execution and post-job results were excellent. This success has opened the way for similar jobs in this and other of the operator's fields.