Vertical Steam Flood Heavy Oil developments, such as Shell's Carmon Creek project, require a large number of wells. This high well count leads to the wells contributing a large part of the project cost and a large physical footprint. In the Carmon Creek project, the challenge for Shell was to safely drill and complete thousands of wells at the lowest possible cost while minimizing the footprint. The approach taken was that of a ‘Wells Manufacturing System’, using new technology, bespoke equipment and novel ways of working. The well construction operations were broken down in repeatable steps. This enabled fast learning and it provided the basis to engineer out ‘flat-time’ activities by designing fit-for-purpose equipment, such as BOP systems, wellheads and drilling rigs. Partnerships in low cost manufacturing locations were formed to build this equipment. A multi-disciplinary team designed wellpads, not only making them as small as possible, but also to enable the implementation of an assembly line philosophy. Three-dimensional well planning was crucial to establish the optimal well spacing at reservoir level. Drilling performance in similar developments was benchmarked extensively to be able to set challenging targets and to be able to measure performance. Given the application of the wells manufacturing system, using the same well design for both injector and producer wells was deemed most cost effective, since the key to the success of the manufacturing philosophy is repetition. This saves time and optimizes the supply chain. The resulting wellpad design has an unprecedented well count per pad of up to 49 wells, positioned in a single line. The well spacing was driven by how close beam pumps can physically be placed. The fit-for-purpose rigs have substructures that cover three wells simultaneously and function in essence as self-walking assembly halls, furnished with a super-single drilling mast. The rigs are equipped with double BOP's that can leapfrog. Work on three wells is performed simultaneously and activities such as BOP testing and waiting-on-cement are taken off the critical path. The rigs were built and operated by a Shell Joint Venture, blurring the boundaries between the traditional roles of operator, drilling contractor and Service Company, based on three principles: Build a Long-term relationship that allows Continuous Performance Improvement Technology that results in fit-for-purpose (FFP) equipment Very attractive pricing that is not coupled to North American market volatility Drilling commenced in 2014 and performance has been excellent, particularly with learning by repetition exceeding expectations. The Project itself was cancelled due to political and economic reasons, but drilling on two pads was completed prior to the project halt. In total, 92 wells were drilled, with 65 wells achieving ‘Best in Class’ time and cost performance, and 77 Top Quartile wells. Well times and costs as a result decreased by up to 50%.

Shell has experienced production casing deformation on several infill wells in an existing thermal development project in Canada. A full investigation identified trapped annular pressure (TAP) caused by unreacted water fraction in set cement between casing strings as a potential casing failure mode. A novel and innovative application of an existing technology (a cement blend incorporating hollow-glass microspheres) was developed, tested and implemented as an effective means to provide pressure relief in the cemented casing-casing annulus on steam injection wells. Thermal cement blends from two suppliers were used in the testing program. The test slurries were cured in a test cylinder until compressive strength development tapered off, and then heated in increments to 320°C while pressure was recorded. Typical thermal blends containing a range of concentrations of hollow-glass microspheres were tested in this manner to establish a slurry design that would prevent the pressure build up from surpassing the temperature de-rated collapse resistance of the casing. The tests using typical thermal cement blends with no glass bead additive resulted in rapid increase in pressure as the test cell was heated, and exceeded the temperature de-rated collapse value of the production casing string at temperatures much lower than typical steam injection temperatures. Tests performed on blends containing the glass spheres showed consistency and repeatability in results, and pressures were well below the de-rated collapse pressure of the production casing string at the maximum steam injection temperature. Based on preliminary results, this investigation has concluded that the cement blend containing 10% BWOC hollow-glass microspheres is a viable alternative to conventional thermal blends, capable of providing hydraulic isolation to meet regulatory requirements and industry best practices, with the added benefit of providing a mechanism to mitigate TAP on steam injection wells.