A common production strategy from heavy oil sands is to produce the sand with the oil to maintain, or even increase, the deliverability of the well. Where very high sand production is realized, the cumulative sand volume 'mined' from the reservoir can be very large. This can result in large vertical deformations relative to the elastic strain limit of steel and associated deformation of the liner through the producing interval. A new completion system has been developed to address the deformation associated with very high sand production wells. The Compaction Resistant Wellbore (CRW) was designed to absorb the axial compaction strain and improve structural capacity. Strain-absorbing tools accommodate axial deformation and preserve the elastic characteristics of the pipe. A new type of completion tool through the producing interval provides substantially increased compression strength and buckling resistance to distribute deformation to the strain-absorbing tools. Although the system is novel, it can be run with only slight modifications to conventional procedures. Introduction Cold heavy oil production with sand (CHOPS) has proven to be an effective strategy for increasing recovery rates to levels significantly beyond conventional practice. However, experience with this strategy also demonstrates that where the strategy is most successful, well life is often reduced by deformations due to sand production. Bent and buckled casing often compromises the pump and prevents well access to facilitate repair. Tension failures in the cap rock above the reservoir compromise pressure integrity, resulting in higher abandonment costs. While the improved productivity generally offsets the cost of such problems, there is substantial opportunity for improving the economic performance of the sand-producing strategy if the problems associated with reservoir compaction can be reduced or eliminated. Much attention has been focused on compaction-induced problems over the past 20 years in the oil industry. Many issues have been characterized, and a variety of solutions have been proposed. In this paper, deformation mechanisms are reviewed, considered in the context of a high sand production strategy, and a solution for extending the life of such wells is presented. A case study of a high sand-producing field is reviewed, showing a history of well operation and the implementation of this approach for increasing the well life. Background Many modern production strategies in the oil industry achieve very high recovery rates in reservoirs where the void space containing the oil can be reduced by production. Examples include North Sea chalk reservoirs, like Valhall(1) and Ekofisk(2, 3), where compaction drive produces superior recovery rates. While production associated with compaction is a significant benefit, the cost associated with compaction is also high. Subsidence and casing deformation problems arising from compaction can be difficult and costly to characterize and mitigate(3–6). Completion performance is also a challenge because of the high compaction strain relative to the completion limits, often exceeding ten times the yield limit of steel. One solution that has been proposed to solve this problem is to use slip joints in the casing or liner to absorb compaction strains so the well structure can accommodate axial deformation without exceeding tensile or compressive limits(7).

Opportunities to improve rig floor safety, reduce risks and reduce costs have motivated operators to utilize the top drive for casing running operations. Simple and easy approaches for applying make-up torque and hoisting loads to the casing string have been used with some success, but in some applications performing these functions safely, economically and without connection damage has not been trivial. Operational logistics, management of loads that cause casing thread damage and prevention of pipe body damage are examples of challenges requiring sound technical solutions. Pipe handling logistics, including engagement of the casing grip, must be executed efficiently without damaging casing threads or sealing surfaces. Similarly, bending loads resulting from rig misalignment or casing curvature can initiate thread damage if uncertainties remain unmanaged. Finally, local cold working of pipe body material increases stress cracking susceptibility, particularly on inner surfaces, and may reduce casing string reliability. Successful use of casing running technology depends on selecting a system that meets the technical requirements of the application. A sound understanding of casing thread make-up, drilling rig operations and the interaction between the two enables critical evaluation of emerging technologies and reduces the risk of commercial failure. This paper presents the background behind such evaluation and discusses a range of technologies in the context of that background. Introduction A desire to improve rig floor safety and eliminate unnecessary expenses has motivated oilfield operators to utilize the top drive for casing running operations. Applying make-up torque and hoisting the casing string can be accomplished quite easily, but performing these functions safely, economically and without damaging the casing body or connection threads and seals is not a trivial task. Several top drive casing running systems are commercially available, but consistently successful deployment requires that users carefully match technology with applications. Technical challenges are described here and solutions are characterized in an application- specific context. Successful exploitation of this emerging technology will occur more reliably with an understanding of the relationships between pipe, casing threads, running equipment and drilling rig operations. The simplest way to transfer torsion and axial load from the top drive quill to the casing is with a crossover, commonly referred to as a nubbin or make-up quill, from the top drive to the casing thread. This approach is widely used in western Canadian shallow hole applications, but fails to capture the full safety and economic benefit available through top drive casing running systems that engagethe pipe body rather than the casing threads(1). Specific top drive casing running tools are used in a broad range of applications. Success has been reported for casing runs in:highly deviated Gulf of Mexico wells(2);river crossings(2);onshore horizontal wells(2);desert wells(3); and,the North Sea(4).Compelling business cases for adopting top drive casing running systems have been published previously(1–4) and the subject will be treated here at a summary level only. The positive economic impact of using top drive casing running systems is evident in three areas.