Field-testing of new drilling tools introduces increased health, safety, and environmental (HSE) risks due to the unfamiliarity of the personnel with the new equipment and its operation. This paper presents a unique overview of the HSE challenges that were faced when an entirely new drilling system, not just the individual components, underwent its first field trial.
The Advanced Well Construction System (AWCS) introduced many new technologies, including Advanced Composite Coiled Tubing (ACCT), a downhole propulsion unit, and a hybrid rig design. By using a lightweight carbon-fiber pipe, the system was designed for geological steering of complex, slimhole wellpaths. The system incorporates three major subsystems: digitally controlled and automated surface equipment, a 3 1/8-in. composite drillstring with embedded wires, and an electronically controlled bottomhole assembly (BHA). This system is designed to economically harvest hydrocarbon zones that were previously bypassed and to find and exploit new reserves from existing idle offshore wells.
Beginning with the initial feasibility study, both the oil company and the service company made a commitment to adhere to the highest HSE standards in all phases of the project. The resulting HSE program was derived from the knowledge, experience, and established procedures and processes of professionals throughout both organizations.
This case history presents details of the HSE program jointly developed and implemented by the service company and the oil company as part of a qualification program for this unprecedented drilling system. Evolution of the HSE program from project planning, through the HAZID/HAZOP processes, and on to full implementation during the drilling phase is examined. A detailed description of the cultural, engineering, and logistical challenges that were overcome during the implementation of the HSE program is provided. A discussion of the HSE program summary results and "lessons learned" during the project is also included.
Introduction
An operator found a suitable target well for the new system in the GOM. During the evaluation processes, a decision was made to combine a hydraulic workover unit (HWO) with the AWCS. The HWO, or snubbing unit, was incorporated into an integral tower. The primary purpose for incorporating the HWO unit was to provide a means of conveying jointed tubulars (drillpipe, casing, and completion strings) into and out of the well as required. This "hybrid drilling system" had never been used before and both companies recognized the risks involved in combining these systems for the first time. Fig. 1 shows the hybrid drilling system.
The project management team organized HAZID and HAZOP sessions to address and define their concerns about applying this new system to drilling an offshore well candidate. These sessions resulted in the decision that before the target well was started, a mimic wellpath should be drilled to test how the two systems would work together. After several sites were evaluated, a chemical plant facility in south Texas was found to have the lithography that was the most similar to the offshore well. The similar lithography facilitated both the drilling of the mimic path and the qualification processes of bringing the two systems together to evaluate possible problems. Additionally, the proposed facility was an open, secure and isolated area on private property to which the equipment could be easily mobilized so that the well could be drilled with minimum interruptions.
