Note: The final report consists of an Executive Summary, the PhD Thesis of Ray Oskarsen and the MS Thesis of Sam Noynaert. This project did not continue under Phase II. Abstracts for the two theses appear below.
Over the last decades exploration for hydrocarbons has been rapidly moving into unconventional reservoirs such as ultradeep water. Because no guidelines and procedures for blowout containment in ultradeep water are currently available, a project has been undertaken to develop them. Developing and validating the procedures requires a dynamic-kill simulator, but no available dynamic-kill simulator can perform all the simulations necessary. Therefore, the project chose to develop its own simulator that can model dynamic kills for surface, subsurface, and underground blowouts for modern drilling techniques. This dissertation describes the development of that simulator. Some of the main features and advantages of this dynamic-kill simulator include:
- A user-friendly interface.
- Choice between stand-alone or Web application.
- Surface, subsurface and underground blowout capability.
- Simple dual-gradient drilling.
- Both Newtonian and non-Newtonian kill fluids.
- Oil and gas reservoirs.
- Rigid temperature models.
- Fluid properties adjusted for pressure and temperature effects.
- Sonic flow considerations.
- Three multiphase models accounting for slip between phases.
The simulator is validated using simple analytical solutions and production data. In all cases the simulator gives reasonable and meaningful results. The simulator is also used to study the effect on blowout intervention as drilling is moved into deeper and deeper water. Results show that as water depth increases, the intervention requirements become more demanding. Because of the high flowrates and horsepower needed, a blowout in ultradeep water will likely require more than one relief well for successful blowout intervention.
The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world’s hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water.
While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company’s exploration planning and technology suite.
To further the development of blowout prevention and control, COMASim (Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements.
The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim’s strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.