河道砂体解剖技术在低渗透油藏的应用

APPLICATION OF CHANNEL SANDBODY ANATOMIZING TECHNIQUE IN THE LOW-PERMEABILITY OIL RESERVOIR

C油田C55区块是典型的低渗透裂缝性油藏,目前处于一次井网加密后的中高含水开发阶段,主力油层水淹严重,层间矛盾较为突出,层间干扰型和高水淹韵律顶部型剩余油富集。目前尚缺乏有效动用低渗透储层高水淹韵律顶部型剩余油的水驱挖潜方法。通过检查井岩电对应、加密井测井水淹解释和注入剖面资料发现该区块5个主力油层存在发育上、下2个砂体的情况,为此应用河道砂体精细解剖技术进行储层细分,将层内矛盾转化为层间矛盾,使高水淹韵律顶部型剩余油转化为层间干扰型剩余油,通过注水井的精细分层调整,改善了层间动用状况,提高了油田开发效果。

Block C55 in Oilfield C is typical low-permeability fractured oil reservoirs. At present, it is in the mid- dle-high watercut stage after the first infilling of the well pattern. The main oil reservoirs are seriously flooded ; the interlayer contradictions are more prominent and serious. The remained oil is generally enriched in the interlayer in- terference-type layers and high waterflooded-type rhythm reservoir top. So far, the potential-tapping method by wa- ter flooding is still lacking for effectively developing the latter remained oil in low-permeability reservoirs. With the help of the rock-electricity correspondence among the inspecting wells, watered-out logging interpretation for the in- filled wells and injection profiles＂ data, two upper and lower sandbodies are found out in five well-developed main oil layers of the block. Then the fine stratification is conducted by means of finely anatomizing technique for the riv- er channel sandhodies, so the internal contradictions can be transferred into the interlayer ones, and moreover the latter remained oil can be changed into the former one. By the fine stratification and adjustment of the water injec- tors, the interlayer developed status is improved, thus the development effects of the oilfield are enhanced.