A technical report aimed at providing consistency in high-pressure, high-temperature (HPHT) practices is being prepared by a group of API task groups consolidated as the Executive Committee of Standardization. The effort aims to meet the intent of the Minerals Management Service NTL No. 2007-G07 on HPHT equipment and operations that will become a regulation later this year. The committee, “Protocols for Equipment Rated Greater than 15,000 psi (PER15K),” will provide the report to a number of subcommittees that will use the information as they see best, said Earl Shanks, chairman of the Deepwater Technology Company and chairman of the API PER15K Design Validation Work Group.
“The objective is to stand as a product that will provide consistency in the development and evaluation of HPHT equipment,” Mr Shanks told attendees at the 2009 IADC Well Control Conference of the Americas & Exhibition in Denver on 26 August.
The API report maps out a process for HPHT equipment that will
require both design verification and design validation.
Specifically, the report maps out a product development process for existing or new design equipment that will require both design verification and design validation. Design verification activities may include confirming the accuracy of design results through calculations; review of design output documents and comparing new designs to similar proven designs, Mr Shanks explained. Design validation includes prototypes tests, testing of production products, tests required by the industry or regulatory agencies and field performance tests and reviews, he said.
The project basis of design addresses such as issues as location, subsea or surface, the environment the equipment will be subjected to, the pressures, the temperatures, the environmental exposure for the equipment and materials and the anticipated life cycle operating performance of the equipment.
“The system has to be looked at as a whole, not by individual components,” Mr Shanks emphasized. “We need to understand how interfaces put loads on individual components. This report outlines various methods of analytical design verification intended for HPHT pressure-containing equipment in the petroleum and natural gas industries, where HPHT environments are intended to mean one or more specific well conditions exist.”
Such conditions include well control equipment with a pressure rating greater than 15,000 psi or a temperature rating higher than 350°F; surface or shut-in tubing pressure greater than 15,000 psig on the ocean floor for a well with a subsea wellhead or at the surface for a well with a surface wellhead; flowing temperature that is equal to or greater than 350°F on the sea floor for a well with a subsea wellhead or on the surface for a well with a surface wellhead.
“The design validation is the testing part,” Mr Shanks continued. “The intent is to confirm the design verification. The same issues that were studied in the verification and analysis need to be simulated as closely as possible in the validation testing.”
Testing is being designed to examine such things as in-service load conditions and measure and monitor peak stresses. The report also identifies a number of product and manufacturing elements, such as inspection, materials, purchase specifications and repair.
PER15K is expected to review the first draft of the report in October and present the final draft at the winter API meeting in January.