Abstract
This paper will present two unique fishing operations using a Snubbing unit and Workover rig to recover a 10,500 ft of 1%" High Pressure Coiled Tubing (HPCT) that got stuck in a new deep gas well in Saudi Arabia while performing the post-frac proppant clean out operation.
A snubbing unit was used to fish the stuck HPCT. The objectives were (1) to fish the 10,500 ft of the 1%" HPCT, and (2) to clean out the well to the Plug Back Total Depth (PBTD). Therefore, a scope of work was prepared that included calculating the free point of the stuck HPCT, running with a chemical cutter using electric wire line and cutting the HPCT above the free point, and laying down the HPCT. Then, run with 2%" washover pipe and clean around the HPCT by swallowing it several times until the remaining HPCT is retrieved and finally, clean out the remaining proppant/PropNET from the wellbore. (PropNET is a fiber pumped at the end of prop-frac treatment for solids flowback control.) The snubbing operations recovered ±9,400 ft of HPCT out of 10,500 ft and the operation was terminated due to no progress after encountering the chemical cutters that were lost during the fishing operations.
The snubbing operation results were studied and used in planning for the rig workover operations. The preparation of the workover included discussing with fishing specialists the different fishing scenarios, identifying and ordering all tools and equipment that may be needed in the operations and putting together contingency plans. The objectives of the workover were to retrieve the remaining HPCT, fish the lost chemical cutters that were left in the hole subsequent to the fishing operations with the snubbing unit.
The paper will discuss the different techniques used in both operations and will highlight the lessons learned from both operations.
