In recent years, re-invention and development of electrical wireline mechanical applications, initially for high-angle well-access in conjunction with wireline tractors, has proven able to unlock value potentials in production enhancements efforts by allowing interventions, previously thought impossible or cost prohibitive, even in low angle wells.
A wireline tractor enables wireline tools to be conveyed in high angle and horizontal wells whereas downhole mechanical operations such as shifting sliding slide doors (SSD), setting a bridge plug or straddle packer in highly deviated wells can be performed on wireline utilising the wireline stroker technology. Downhole obstructions such as scale or stuck isolation valves can also be milled out on electric wireline with a wireline miller deployed in conjunction with a wireline tractor.
There have been many successful applications of the wireline tractor technology in the oil and gas industry because of the benefits associated with the cost efficiency, smaller equipment spread, less number of personnel required during the operation, shorter operational duration amongst others.
First example of this technology to be illustrated in this paper is the successful application of the wireline stroker used as an anchor to set a bridge plug in a well with high cross flow. The bridge plug was set at 3,165 m MD in 1,887 bbl/day cross flow with a pressure differential of approximately 30 bar in a 5” liner. After setting the plug, a wireline tractor successfully installed a 7 m straddle across 3,045 – 3,052 m MD in one run to isolate a 3 m water producing interval. After the water shutoff operation, the oil rate was maintained at approximately 1,887 bbl/day, and the water cut was reduced from 90% to 45%. Second case history is the application of the wireline tractor and wireline stroker to repair a well completion in an old producing (mature) well by isolating a stuck SSD with a 22-meter multi-section straddle and then isolate holes in the tubing with an 8-meter single straddle. Well optimization was remarkable with Q oil increased by 900% and water cut reduced from 85% to less than 5%.
Third case history is the successful milling of scale utilising the wireline miller technology. Scale comprising of CaCO3 with a thickness of between 0.1 – 0.7 inches was distributed along 1,631 m interval in an oil producing well. A path of 2.70” was opened in the well within 14 hours from rig up to rig down and an immediate oil production gain of 36 bbl/day was obtained after completing the scale milling operation on electric wireline.
With the proven benefits and reliability of the wireline tractor technology, the applications of this technology is undoubtedly expected to increase and usage will continue to be in the uptrend corresponding to the increase in well intervention activities as part of the field production enhancement efforts of global oil operators.