关键词: 致密油藏, 压裂驱油, 体积压裂, 注水增能, 焖井渗吸, 化学剂驱油

Abstract: Aiming at the difficulties in flooding and production of tight reservoirs, the integrated fracturing flooding technology based on the integration of fracturing, flooding and production was proposed. The four development stages of fracturing flooding technology for low-permeability tight reservoirs in domestic oilfields were summarized as follows: matrix imbibition, oil and water displacement recovery; fracture-matrix dynamic imbibition recovery; network fracturing, energy storage and permeability increasing recovery; fracturing flooding, shut-in imbibition recovery. Six technical characteristics of fracturing flooding were determined:(1)to improve fracture control by subdivided volume fracturing; (2)to develop a large number of micro-fractures and expand the swept volume by water injection at near-fracturing pressure; (3)to increase pore throat size and enlarge seepage channel by continuous water injection at high pressure; (4)to supplement formation energy by pre-injection of a large amount of liquid; (5)to enhance oil displacement effect by well shut-in imbibition replacement; (6)adding chemical reagents for fracturing flooding to enhance oil washing efficiency. By comprehensively considering the geological characteristics, action mechanism, process parameters and supporting facilities of fracturing flooding, this paper deeply analyzes the geological and engineering problems of tight reservoir reconstruction faced by China, and proposes four technical research directions for achieving breakthroughs in fracturing flooding in the future:(1)to strengthen the integrated research of geological engineering and optimize the layout of injection-production well pattern in reservoir engineering; (2)to improve the production level of tight reservoirs by deepening the three-dimensional simulation technology of horizontal wells; (3)to investigate the mechanism of fracturing flooding technology, and thus help optimize the process parameters of fracturing flooding; (4)to reduce the cost and increase the efficiency of tight reservoir development by improving the supporting technology of low-cost and high-efficiency fracturing flooding.

Key words: tight reservoir, fracturing flooding, volume fracturing, water injection for energy enhancement, shut-in imbibition, chemical flooding