Well Intervention Challenges in Mega-Reach Wells with Coiled Tubing and the Application of the Latest Technologies in Tackling These Challenges, Saudi Arabia

Abstract

With the growing demand for oil production, and pressure maintenance for giant fields, more horizontal wells has been drilled as power water injectors and oil producers to increase the contact with the reservoirs. In M-field, many wells are drilled as mega-reach with a measured total depth up to 33,000 ft. This present a big challenge for coiled tubing intervention to reach TD and stimulate or perform logging. Even with the use of hydraulic tractors, CT Pipe Locks up before TD, and it has been difficult to understand the root cause as it is not possible to differentiate between a hydraulic tractor malfunction and downhole obstruction causing the CT to tag. Here in this paper we are going to illustrate the reach challenges, analysis performed on the un-anticipated lockups, and how could we utilize recent technologies in understanding the lockup occurrence, as well as quantifying the how can we improve the prejob tubing force model simulation to fine-tune well accessibility in real-time while on the job. With the implementation of the real-time tension-compression tool, it becomes possible to detect any malfunction of the hydraulic tractor. With the real-time reading of the tractor pull downhole, the coiled tubing force model simulation can be adjusted during the operating to match the real coiled tubing weight and have better estimation of the expected lockup depth. Real-time informed decisions can optimize the CT reach. Being in ultra heavy oil formation and barefoot completion, the following questions come to the scene: Are we tagging in tar? or it is just the excessive drag force that is causing an early lockup?; What if the tractor fails? and how to diagnose the failure?; Shall we use solvents? at what quantities if any?; Is it feasible to run more than once? or it is a challenge that we cannot overcome? All the above questions are answered in details in the paper with illustrated troubleshooting, and problem solving workflow that is aided by case studies, jobs results, and success stories from one of the biggest fields in the Middle East. Exploring more in this direction would successfully change the face of the tubing force model simulation algorithms and take the on-site operational excellence to a significantly advanced level.

Advanced Understanding of Matrix Stimulation Treatments Through In-Job and Post-Job Evaluation of Real-Time Downhole Measurements with Coiled Tubing: A Case Study

“…Both techniques can utilize mechanical (e.g., bridge plugs, packers) and chemical (e.g., particulate diverters, self-diverting acids, and foams) means for diversion of the treatment fluids. Currently, CT is the preferred method to stimulate horizontal wells because it offers the best compromise to make sure fluids can reach the target zone, even in extended reach scenarios where CT can be complimented by the use of tractors to reach further (Dhufairi et al 2013). In addition to its conveyance advantage, CT can also facilitate real-time monitoring and decision-making thanks to the presence of downhole sensors and a fiber-optic line placed within (Cantaloube et al 2010;Garcia et al 2011;Garzon et al 2010).…”