Merging Tapered in Coiled Tubing (CT) and Well Tractor Technologies to Effectively Stimulate Extended Reach Open Hole Horizontal Wells

Abstract

The M field development involves one of the largest drilling projects in Saudi Arabia, targeting various carbonate reservoirs, and with an extraordinary amount of extended reach wells (ERWs) requires meeting the expected oil production rate, at the lowest development cost possible. More than two-thirds of the wells fall under the extended reach drilling classification, and the majority of the wells have measured depths (MDs) between 24,000 ft and 31,000 ft. These wells are open hole completions where acid stimulation is highly needed to overcome reservoir damage and improve the well's performance after drilling operations terminate.The placement of the treatment fluids requires a uniform distribution along the open hole section. Among the different techniques considered, namely bullheading, using the rig drill pipe and coiled tubing (CT), the last one offered the soundest technical and cost option. However, the CT technique alone did not show the ability in reaching the maximum depth in most ERWs of this field. Therefore, the tractor 1 was required to provide the significant amount of pull force needed to operate inside these long distances, not seen before in open hole completions.The first eight well campaigns, using a combination of CT, a hydraulic tractor and friction reducer fluids, have achieved the main objectives. Moreover, a new intervention world record 2 was set when the CT bottom-hole assembly (BHA) reached the maximum depth of 28,257 ft inside open hole in two different occasions, to place the stimulation fluids, and to record an injection profile. During the campaign, a total of 41,774 ft accumulated footage has been operated with the tractor, allowing over 3,400 bbls of acid to be placed in direct contact with the formation. As a result, the average injection rate has increased more than tenfold, reducing the drilling requirements for injection wells originally projected.The job preparation, technology, results, learning curve experience and best practices are discussed in this paper, including proposed operational enhancements. This experience demonstrates the feasibility of the operations with CT required for full zone coverage, yielding optimum water injection rates at the lowest development cost.

Surpassing the Challenges of CT Interventions in a Trilateral Extended Reach Well in the Arabian Gulf

“…Several extended reach wells have also been intervened with CT, in the UAE (3) and regionally (4), (2) , in the past decade. However, MRC-X is the first well with the combined challenge of trying to gain lateral access and then maximizing CT reach.…”

Innovative Coiled Tubing Equipment for Successful Temporary or Permanent Zonal Isolation

“…The stimulation job results will be used to estimate the number of future producers/injectors required, as well as to evaluate the future well's configuration across the tight formation [3][4][5] . The job objectives were to check the swellable packers' integrity and to stimulate the dual laterals to remove the suspected formation damage using CT and a multilateral tool to access both laterals.…”

Stimulation With Innovative Fluid-Placement Methodology and World First Production Logging With Fiber Optic Enabled Coiled Tubing (CT)

“…The current approach is to use a memory PL tool (PLT), with the associated drawback of missing/poor data quality and possible eventual misruns (Al Dhufairi et al, 2010). This paper will address the ERW stimulation challenges from CT operation to fluid placement and diversion ending at the post job efficiency assessment.…”