John Thorogood

Delivering World-Class Exploration Drilling-Integration of Design, Planning, and Execution

Over the last 2 years, a series of organizational structures, systems, and processes produced outstanding results from a five-well exploration drilling program that involved three different rigs and teams. Risk assessment is a key thread that runs through the process, from high level risks in a conceptual design to details of day-to-day execution. It is robustly linked to the process for estimating well times and contingency costs and provides a means of communicating risks to business delivery up to management. A correct set of well objectives and design basis is the foundation of an effective detailed planning phase involving a large team of contractors. Integration of service suppliers and drilling contractor into a comprehensive planning effort is key to planning and execution success. Standard project-management techniques are combined with structuring of the organization around delivery of key elements of the well to ensure that a large project team is properly focused on achieving a world-class operational target. Detailed planning ensures flawless operation and efficient recovery from setbacks. The rig team is critical to getting the detail right. In the end, rigorous post-analysis is essential to ensure that lessons learned, not only about the technical aspects of the well, but also the process, are fed back into the planning of future operations.

Drilling Automation: Potential for Human Error

Mode confusion is an automated system behaving differently than expected and the operator not being aware of (or not properly understanding) what the system is doing. Mode confusion is wellrecognized in the aviation community and has been indicated in a number of high-profile aviation accidents. As an example, a JAS Gripen fighter jet crashed during a test flight in the 1980s because the pilot tried to manually correct instability while the plane’s computer was automatically trying to do the same. The potential for the same type of problems, and associated safety hazards, arises in drilling-rig operations as a result of the increasing trend for automation and advisory systems. A simple example could be formation fracturing with an automated downhole pressurecontrol system when displacing to higher mud weight caused by the driller relying on the automated system to maintain sufficiently low flow rate without having reconfigured the system with the new mud properties. This paper describes how the use of a drilling support system in different modes and levels of automation may influence the system operator’s performance and risk of human error. The development of a systematic method for detecting mode-confusion problems by model checking is central in this respect. The test cases have been simulated in a virtual test environment created at IRIS specifically for such purposes. The test environment and test cases are described, and results are reported and discussed.

Risk management in exploration drilling

In late 1997, BP Amoco realized that a step change in drilling performance, including health, safety, and environment (HSE) performance, was necessary to sustain the future of the Norwegian operation. A review determined which factors contributed to successful exploration drilling projects. A detailed planning process was developed and underpinned by a set of Ten Principles. Identifying, understanding, and managing the HSE and financial risks involved in an operation are vital to achieve world-class levels of performance. A key feature is how risk assessment is integrated seamlessly into the project workflow.

Directional Survey Operations Management

The survey program for any well can be based on three general rules: tools intended for use in a well must be qualified for the application; accuracy objective must be specified for each well; and the proposed program must be shown to satisfy the wells objectives. The purpose of this paper is to review some of the issues underlying the management of survey programs and to encourage the end users of well survey data to adopt a critical discriminating attitude toward the information on which they base important reservoir engineering and petrophysical decisions.