Directional Tapping Technology of Residual Oil in Carbonate Reservoir

It has been nearly 30 years since China petroleum entered into overseas cooperative development. The Middle East and Central Asia are the main cooperative areas, and carbonate reservoirs are the main reservoir types. After more than 20 years production, most projects have entered the late stage of oil and gas field development. High output, high water cut, high recovery, and low production rate, low pressure and low efficiency are the recent facing development problems. How to tap the potential of remaining oil economically and effectively is a key point that restricts the sustainable and efficient development of oil and gas fields. Through reservoir static evaluation, reservoir numerical simulation, reservoir elaborate description, residual oil and dominant channel inversion, the remaining oil enrichment area is optimized and determined, and the targeted development strategy is determined. The technical system of directional sidetracking and staged completion, staged fracturing, integrate production system of old wells was established. Corresponding key tools, such as large-size and high-pressure gas lift valves were developed. Aiming at the residual oil in the thin layer, low permeability and low pressure area at the edge of the structure, the key tools and technical system of coiled tubing drag acid-fracturing are developed. The integrated stimulation technology series of reservoir, drilling and completion, fracturing and gas lift oil production is established. The directional tapping technology of residual oil in carbonate reservoir has been applied in Central Asia project for 42 wells. The oil production has been increased by over 450,000 tons. It is of great practical significance to achieve the aim of effective development of residual oil and gas in reservoir.