Gas lift valves are an integral part of the tubing in gas lifted wells. Many operators use tubing with premium threads for these wells. Additional safety equipment, including the packer and the downhole safety valve, has been subjected to a program intended to prove its capabilities as a safety device. This is not the case with standard gas lift valves, developed and delivered according to the governing standard, ISO 17078-2. On the contrary, this standard states that the valves are only intended to be a flow check and not a pressure safety device. This paper discusses the development of a new validation standard, where the intention is to prove the equipment's safety capacity, as well as new equipment developed to meet these challenges.
Most operating companies design their wells according to external or internal regulations with respect to safety equipment and safety levels. Each component needs to meet material standards and specific equipment standards. The standards will also describe production requirements as well as acceptance testing procedures for the equipment in question. New equipment typically has to be qualified to a certain validation procedure described in a standard issued by an external standards organization and often to additional internal company requirements.
The safety philosophy of preventing uncontrolled release of hydrocarbons is often referred to as barrier philosophy. The barrier philosophy for a given well typically depends on region, nationality and operating company. The Norsok D-10 is an example of a standard describing elements preventing hydrocarbon or pressure release to the atmosphere and it defines well barriers as; " Well barriers are envelopes of one or several dependent well barrier elements preventing fluids or gases from flowing unintentionally from the formation, into another formation or to surface. The well barrier(s) shall be defined prior to commencement of an activity or operation by description of the required well barrier elements to be in place and specific acceptance criteria.??