Today, oil and gas industry is witnessing rapid evolution of deep-well drilling technique in which the initial hole size doesn’t affect bottom diameter of the well. This technique relies on the use of expandable casing strings to isolate formations with different pressures, as well as caving and sloughing zones. Two principle ways to improve economic efficiency of oil and gas production using expandable technologies are the following: 1) material and time saving due to nonconventional well design using expandable casing strings; 2) oil recovery enhancement due to development of equipment for surface-controlled oil production fr om pay zones with different characteristics.
This paper reviews a conventional telescopic 10-string well design and a 10-string design of well No.18 (Tatneft-Samara ZAO) wh ere expandable profile liners were used for trouble zone isolation. Expandable technology provided significant reduction of material and energy consumption during well drilling and construction operations in complex environment; so, the authors can recommend this technology for application in marine drilling. This paper points out the potential for substantial increase of oil production rate through decreasing wellstream watercut due to controlled fluid production from several pay zones with different porosity and permeability characteristics. Development of fluid production control system comprising cableless electric valves is the most promising focus area. Capital expenditures related to development of small-area oil fields can be significantly reduced by drilling multilateral horizontal wells.
