Sand Control in the Wells of SOCAR Oilfields

Abstract

Prevention of slightly cemented formation destruction and dispersed solids (sand and clay) removal is a complex and hitherto unsolved problem. The stability of the bottomhole zone is closely connected with geological and petrographic characteristics of the target formation and technological mode of producer wells operation. Sanding causes such complications like sanding-up, erosion of downhole and surface equipment, elimination of which requires significant financial costs. The adequate choice of bottom-hole zone stabilization, careful adherence to the elements of technological process are necessary conditions that guarantee technical and economic efficiency of works.A variety of activities and methods are used in wells of ЉAzneftЉ PU to eliminate foregoing shortcomings, i.e. for sand control. Sand control activities mainly cover four areas: adaptation of gravel-slotted filter, drilling-in with no perforation, producing sand consolidation, sand plugs removal by means of tools.Positive results have been obtained in the result of gravel-slotted filter application in 230 sanding wells. Drilling-in of weakly cemented formations with no perforation is carried out with or without the filter. Producing sand consolidation is realized using different technologies: control of physical and mechanical properties of the cement slurry, as well as cement slurries with various additives and polymer-based cement slurries.Acid-based cement slurry is proposed to clean sand supplied from reservoir. Introduction of this technology creates a stable and permeable barrier in the near-wellbore zone that prevents or completely restricts sand entry.In intake wells hydraulic, hydromechanical and wireline instrumentation is used to prevent the ingress of washing liquid for sand-bridge removal.Prevention of slightly cemented formation destruction and dispersed solids (sand and clay) removal is a complex and hitherto unsolved problem. Extraction of fluids from slightly cemented formation is almost always accompanied by sand carry-over. The intensity of sanding in production wells reduces the ultimate recovery resulting in lead to a large overhead costs for production, transportation and preparation of products, equipment repair. Sand appears as a result of a two-step process as affected shearing stress, breaking rock formation. Formation fluids then carry chipped sand into the wellbore and then to the surface or it settles at the bottom, as well as elsewhere in the downhole system [1].The stability of the bottomhole zone is closely connected with geological and petrographic characteristics of the target formation and technological mode of producer wells operation. Regardless of the

Development of composition of cementing slurry for fastening of low-cemented rocks

“…An acid-based cementing slurry is used to strengthen the rocks in the bottomhole formation zone of the Socar field [18]. The strengthening creates a stable and permeable barrier that prevents sand entry into the well.…”