关键词: 特殊工艺井, 特殊油气藏, 分支井, 鱼骨井, 套管开窗, 储层保护

Abstract: Now low-permeability reservoirs, heavy oil reservoirs, fault-block reservoirs, and other special reservoirs have become main replacement blocks of some old oil provinces in China. They are difficult to be developed economically by using conventional vertical well technology and horizontal well technology. Non-conventional well technology represented by branch horizontal well technology could achieve the goal of developing multiple reservoirs at the same time by corresponding one wellhead with a number of underground boreholes, increasing the exposed area of reservoir significantly and enhancing oil-gas recovery and sweepout of reservoir. After briefly introducing the difficulties in special oil and gas reservoir exploitation, this paper introduces the systematic non-conventional well drilling technology, well trajectory control technology, special well completion technology and reservoir protection technology in details, and points out that they have been used to nearly 80 branch wells including more than 60 fishbone-branch wells, with the success rate of drilling and completion reaching 100% and the high-grade cementing rate higher than 90%, fulfilling economic and efficient development of special reservoir and providing valuable experience for development of similar special reservoir.

Key words: non-conventional well, special oil and gas reservoir, branch well, fishbone well, casing window, reservoir protection