I believe you have to look at the complete life cycle, starting with the purchasing guide lines buy the fittest and not necessarily the cheapest. Selection of the elastomers manufacturer. Is it the Key. Original Equipment Manufacturer? Do they volunteer a suugested life expectancy? Do they offer other meaningfull advice? STORAGE is the major drawback, in general the rigs store the tyres in the dark and BOP rubber spares under the sun, curtailing the life of the elastomeric materials. These should be in sealed envelopes with inert gas, kept in the dark at low temperatures. DURING their use we can increase their life span by flexing the rubber, by closing on a larger diameter - anular seals, for instances - and to the pressure really required and not to the rated pressure of the preventer installed.etc. Some papers of eventual interest IADC/SPE 22452 Elastomers fit for drilling fluids by Hydrill OTC 6583 Ekastomers for drilling in cold climats CEA 39 Behaviour of sealing elastomers PEA-77 Elastomer seal performance CAPCIS SPE/IADC 21960 Conoco´s elastomeric performance MERL Materilas Engineering Research Lab NACE Standards
Augusto CarmonaDaMota -
Posted from Portugal - 2020-02-13 12:48:33replyResponse
My answer would be more about rig practices. We usually take a visual inspection for the packing elements of the rams and the packer of the annular.
Moreover, as far as the annular preventer is concerned, if you increase the annular pressure more and more to have a positive test ( usually it s arround 700psi); that means the packing element is worn.
The regular tests on the rig (once a week for exploration and once in 15 days for development would give an idea about the stat of the BOP)
Mohamed Boumezrag -
Posted from Algeria - 2020-02-10 09:51:56replyResponse
The elastomers are a very difficult client to the point that years ago it was not considered an engineering material, There are useful selection guidelines such as E&P Forum (London), PEA, API 6A and of course the useful guidelines offered by the different Oilfield Equipment Suppliers (Cameron, Shaffer, Hydrill and Koomey at the time). The major hurdle: the Original Equipment Manufacturers - OEM - often sub contract the elastomer elements and that can be a source of headaches even with Custom moulds. Curing is also a challenge. In my experience only a permanent dialogue Operator, BOP suppier and Elastomer designer can ensure proper choice of materials fit for purpose, Elastomer tolerancing, shelf-life, ageing, swelling or shrinking (forcing the use of anti-extrusion devices) and exposure to fluids (drilling or completion ; liquids - chemical ,gasses need a scrutiny that not everybody can master. Even the most mundane storage is neglected: tyres are kept in the dark with air conditioning and the elastomers are exposed to the elements, at list while delivered to the rig awaiting installation. So discuss the issue - in depth - with your OEM and beware of elastomers from copy-cats, apparently - I repeat apparently - cheaper.
Augusto CarmonaDaMota -
Posted from Portugal - 2020-01-30 12:11:38replyResponse