Advanced Completions for Injection Applications (2002)

Advanced Completions for Injection Applications Allyson Gajraj; Allyson Gajraj Schlumberger Search for other works by this author on: This Site Google Scholar Chuanping He; Chuanping He Stanford University Search for other works by this author on: This Site Google Scholar Soraya Betancourt; Soraya Betancourt Schlumberger Search for other works by this author on: This Site Google Scholar Ruijian Li; Ruijian Li Schlumberger Search for other works by this author on: This Site Google Scholar Y. Jalali Y. Jalali Schlumberger Search for other works by this author on: This Site Google Scholar Paper presented at the SPE International Petroleum Conference and Exhibition in Mexico, Villahermosa, Mexico, February 2002. Paper Number: SPE-74392-MS https://doi.org/10.2118/74392-MS Published: February 10 2002 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Gajraj, Allyson, He, Chuanping, Betancourt, Soraya, Li, Ruijian, and Y. Jalali. "Advanced Completions for Injection Applications." Paper presented at the SPE International Petroleum Conference and Exhibition in Mexico, Villahermosa, Mexico, February 2002. doi: https://doi.org/10.2118/74392-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Oil Conference and Exhibition in Mexico Search Advanced Search AbstractWe present results of modeling studies of injection schemes with wells using new completions technology, and address how these are applied or envisaged for the fulfillment of field development strategies in offshore environments.IntroductionA common theme in offshore developments is the use of fewer wells to achieve the production targets of the field. In mature fields, the limited availability of well slots is a severe constraint. In new developments, the drive is towards fewer and smaller platform installations. In subsea developments, particularly in deepwater, the objective is minimization of wellheads. There are clear financial, environmental, and technical reasons for these trends.The use of advanced completions technology to reduce well requirements has been widely practiced in relation to production wells. Commingling of production in layered, compartmentalized, and dispersed geological settings has been achieved with multilateral wells, and conventional wells with flow control technology.1–4 The application of this technology to injection problems has received relatively little attention.5–6The objective of this study is to analyze a number of injection problems that arise from actual field development scenarios. Four cases will be presented. The first two concern achieving proper partitioning of injected water into multi-zone structures. The third case concerns achieving the total target injection rate and partitioning. The fourth case concerns the alternating injection of water and gas.Two-Zone InjectionThis is a deepwater field, being developed by subsea wells. The structure consists of two partially overlapping formations of high permeability (3–5 Darcies), separated by non-reservoir rock. There is no external drive mechanism in the reservoir (e.g. an aquifer). Injection is to commence at initial production. Vertical injectors completed in both formations are to be used. The lower formation has about 1.5 times the injectivity of the upper formation because of its larger effective thickness. The objective is to inject into the upper and lower formations with a split of about 45% and 55% respectively, in line with the estimated distribution of reserves. The operator plans to install fixed and/or variable flow control devices in the injectors. The study analyzed injection options with and without valves. As Figure 1 shows, when no valves are used, the water will spontaneously partition between the two zones in the ratio of about 20% into the upper zone and 80% into the lower zone at relatively low injection rates. As the injection rate increases, so does the frictional pressure loss and this changes the ratio between the upper and lower zones to about 35% and 65%. This is shown in Figure 2. Note, however, that the fracture gradient of the formation imposes a constraint on the injection rate. Figure 3 shows that the desired partitioning can be achieved when both formations are equipped with variable flow control valves. By adjusting the valve apertures, the partitioning of the injectivity can be adjusted as reservoir conditions evolve.Three-Zone InjectionThis example concerns injection into three zones simultaneously, prompted by the limited number of well slots available on the platform from which this reservoir is being developed. In comparison to the previous example, there is greater contrast in the reservoir properties among the three zones, so that the middle zone has the highest injectivity index. The operator has initiated a water injection program for pressure maintenance, using vertical dual-string injection wells (two tubing strings), with the short string injecting into Zone A and the long string into Zones B and C. With this configuration, the approximate partitioning in injectivity is 25%, 50%, and 25% (Figure 4). Keywords: injection pressure, society of petroleum engineers, spe 74392, enhanced recovery, injectivity, water injection, configuration, completion, completion technology, permeability Subjects: Improved and Enhanced Recovery, Waterflooding This content is only available via PDF. 2002. Society of Petroleum Engineers You can access this article if you purchase or spend a download.