A method able to measure the suitability of given subsea equipment to perform a specific duty was documented. A comprehensive assessment of the METHOD was carried out by applying it to one single gate valve.
Using a purpose made validation procedure, this work quantified the weaknesses of the METHOD, brought to light the reasons for these weaknesses and recommended improvements.
The validation concluded that a complete application of the METHOD was not practical. Its present state, the METHOD could not provide the expected useful results and, in particular, did not indicate the tests required on this valve.
THE PROJECT IS AIMED AT DEVELOPING AND VALIDATING A SELF-SUFFICIENT RATIONAL AND INTELLIGENT METHOD FOR QUALIFICATION AND SELECTION OF CRITICAL SUBSEA EQUIPMENT USED TO CONTROL THE FLOW OF FLUIDS FROM HIGH PRESSURE HYDROCARBON WELLS:
- DOWNHOLE SAFETY VALVES (DHSV), DESIGNED TO PREVENT THE UNCONTROLLED PRODUCTION OF HYDROCARBONS FROM A WELL, IN THE EVENT OF DAMAGE OR FAILURE OF SEABED CONTROL EQUIPMENT. THEY ARE INSTALLED IN THE WELL ITSELF SOME 30 TO 50 M BELOW THE SEABED.
- WELLHEAD GATE VALVES, THE MAIN COMPONENTS OF THE PRODUCTION TREE ASSEMBLY AND THE NORMAL MEANS OF ASSURING POSITIVE WELLSTREAM SHUT OFF.
- CHOKE VALVES, REQUIRED TO CONTROL THE FLOW OF HYDROCARBONS FROM THE DIFFERENT WELLS OVER A WIDE RANGE OF OPERATING CONDITIONS.
THIS METHOD WILL CONSIDER THE DUTY CONDITIONS, THE ENVIRONMENT AND THE EQUIPMENT CHARACTERISTICS IN ORDER TO STRUCTURE AND DEFINE:
- AN EXPERIMENTAL PROGRAMME INVOLVING ONLY RATIONAL AND ADEQUATE TESTS.- THE RELEVANT INTERPRETATION PRINCIPLES WHICH WILL PROVIDE THE EXPERIMENTAL ASSURANCE THAT THE EQUIPMENT IS SUITABLE, ALLOW THE RANKING OF VARIOUS EQUIPMENT DESIGNS AND GIVING A MEASURE OF THE CONFIDENCE THAT CAN BE PLACED IN THIS RANKING.
THERE IS PRESENTLY NO SUCH METHOD AVAILABLE FOR QUALIFYING AND SELECTING "STANDARD" EQUIPMENT FOR A SPECIFIC DUTY.
Funding SchemeCSC - Cost-sharing contracts
EC2V 9BU London
BD7 1DP Bradford