ABSTRACT A series of commercially available thermoplastic rubbers have been found suitable for use in downhole and undersea environments. These rubbers require no compounding and can be processed in the low cost manner of a conventional thermoplastic, yet they have the properties of a thermoset rubber. They retain their properties quite well in contact with sea water, brine, corrosion inhibitors and natural gas under pressure at temperatures of -60 to 140°C. These thermoplastic rubbers are finding a growing number of applications in offshore drilling and production. INTRODUCTION Thermoplastic rubbers (TPE's) are a generic class of materials which offer many opportunities for innovation in offshore oil and gas operations. Their use should be considered for any offshore application where a conventional thermoset rubber is now employed. TPE's are already a significant force1–4 in the industrial rubber products market. Their six percent market share should double within the next decade. The TPE growth rate in the U.S.A. is currently 6-8 percent per year, compared to 1–2 percent for the rubber industry as a whole. Thus, TPE's are truly where the action is. A thermoplastic elastomer has the processability of a thermoplastic and the functional performance of a thermoset rubber. Thus, those who know how to process TPE's are in the plastics industry and those who know where and how to use them are in the rubber industry. TPE's offer a major simplification in the process for manufacturing industrial rubber products, with savings in production and quality control costs being highly significant. To the plastics extruder and molder, TPE's open up a new market, previously inaccessible--rubber products. To the traditional rubber processor, TPE's can bring new competition. The practical advantages of TPE's are many:Little or no compounding. Most TPE's are fully formulated and ready for use.Simpler processing with fewer steps, leading to significantly lower cost for the fabricated part.Shorter processing times (i.e., faster cycles). A typical TPE molding cycle is measured in seconds, compared to minutes for the molding and vulcanization of a thermoset rubber.Recycling of scrap (regrind). In thermoset processing, the scrap is usually discarded after each step. For most TPE's, the regrind will give finished parts with the same properties as the virgin material.Better quality control and tighter tolerances on finished parts.Lower energy consumption, a direct result of the shorter cycle times and simplified processing.In most instances, a lower density than that of a comparable thermoset rubber. Rubber and plastics are commonly purchased on a weight basis, but used on a volume basis. TPE's have some disadvantages:New technology, often foreign to many rubber processors and fabricators.Different processing equipment. Most TPE's require equipment familiar to the thermoplastics processor, but unfamiliar to the conventional thermoset rubber processor.