Through-Tubing Inflatable Technology Deployed on a Downhole Tractor System Provides Real-Time Cost Savings

Abstract

Abstract Finding new ways to reduce the costs and production of unwanted water are of paramount importance to the upstream oil and gas industry. The continued discovery of marginal developments, the depletion of reserves from the more mature fields, and a worldwide increase in extended reach and horizontal drilling all provide new challenges on a daily basis. An economical and reliable method of performing zonal isolations and shutting off the unwanted water in these wells can be accomplished with through-tubing inflatable high-expansion devices. However, in the more extended reach and horizontal wells previously requiring coiled tubing or snubbing, there is a new alternative. To meet the reliability, time, and cost efficiency demands of the industrie's current fast pace environment, the downhole tractor system offers an effective new avenue for deployment of these isolation devices. In this paper we will focus on a case history showing how the use of through-tubing inflatable technology run in 3conjunction with a downhole tractor system provides zonal isolation, and savings in time and cost in traditional rig and coiled tubing markets. The other added benefit that is so important is the reduced HSE risk from lighter lifts, reduced personnel and the fluid handling issues surrounded by the use of kill fluids is not needed because the operation is conducted without the need to kill the well. Introduction Over the last century, the oil and gas industry has extended its early exploration and production operations with landbased rigs, wellheads and pipelines to tap the richness of the volume of earth covered by the ocean. This evolution from land to sea started in the late 1890's when the first derrick was placed atop a wharf on the Californian (USA) coast. Since then, seagoing drilling equipment followed, with offshore platforms, semi -submersible and jack up rigs and dynamically positioned drill ships. As offshore technologies advanced to conquer increasingly hostile and challenging environments, offshore drilling moved forward in two major directions; Firstly and more predictably, wells were being drilled in greater water depths and secondly; well-completion equipment entered the water. Wellheads started to be installed on the seafloor, in what is more commonly called a Subsea completion, the first of which was installed in 1961 for Shell in the Gulf of Mexico (GOM). By the year 2000, one thousand Subsea wells had been completed with a future prediction of over three thousand Subsea wells being in place by the year 2009. These wells connect to flow lines that transport the produced hydrocarbons to floating production, storage and offloading systems (FPSOs), neighboring platforms and/or direct to shore-based facilities. Fixed-platform wells have the luxury of continuous well access, where well interventions can be performed routinely without incurring significant additional costs other than for the well intervention service itself. Reservoirs depleted from Subsea well developments are in comparison initially less capital expenditure (CAPEX) intensive; however, due to the lack of routine intervention, the performance of a Subsea well is estimated at only 75% than that of comparable land and platform wells. This 25% reduction in recoverable hydrocarbons is estimated to cost the industry US$10 Billion in gross revenue each year. With this revenue short fall and some fixe d-platform CAPEX measured in billions of dollars, finding reliable and cost effective methods of maximizing reservoir access to Subsea wells can increase production while keeping capital and operating costs down.