Design Verification, Optimization and Validation of Ultra-HPHT Completion and Production Tools

Abstract

Abstract The growing global demand for hydrocarbons is challenging the oil and gas industry to explore and develop deeper and hotter reservoirs, pushing the boundaries of equipment capability beyond traditional High Pressure High Temperature (HPHT) limits into the Ultra-HPHT region. Ultra-HP/HT wells are currently being drilled in the Gulf of Mexico, on the shelf and in deep water. Many of these wells have a total depth of in excess of 30,000 ft, where reservoir pressures and temperatures approach 30,000 psi and 500°F. There are many technological challenges that must be overcome for downhole service and completion tools to operate successfully in the Ultra-HPHT environment. As a result, there are currently few packer-type devices that are considered fit-for-service in these applications. This paper gives an overview of the latest developments in how advanced finite-element analysis tools are used to develop Ultra-HPHT completion and production tools. These advanced analysis tools enable the designs to be verified before prototype and production to determine if they are functional under complex scenarios that sometimes were impossible to validate by testing. A design process that integrates analysis with design and testing for concept verification, design optimization, and test correlation is discussed in detail. The technical challenges of multi-physics simulation like thermal-mechanical coupling, buckling, and 3-D multi-body contact with metallic and hyper-elastic material, are also addressed in this paper through a few Ultra-HPHT completion and production tool design examples. The design process which will be described integrates design verification, design optimization using advanced finite-element analysis techniques, and design validation. It has proven to be a very valuable process in developing state-of-the-art Ultra-HPHT completion packers and bridge plugs for operating conditions as challenging as 500°F and 25,000 psi. Two validation tests were conducted on each of these tools. First, they were tested in accordance to ISO 14310 Grade V0. Then they were tested to a modified grade V3 procedure in as-rolled ID casing, and both passed the tests successfully. A summary of the process and the relevance of each step will be presented, along with conclusions regarding how the process leads to improvements in design and reliability.