Injection-production well pattern construction method suitable for carbonate fractured-cave reservoirs

Abstract

The invention discloses an injection-production well pattern construction method suitable for carbonate fractured-cave reservoirs and relates to the technical field of oil and gas reservoir development. The method includes the steps that the types of carbonate fractured-cave structures are recognized; according to different types, the fractured-cave structures are depicted; the correlation of communicated fractured cave structures in fractured caves is analyzed, and a fractured cave reservoir body communicated structure is built; used reserves and control reserves of fractured cave reservoir bodies are calculated and marked; an injection-production well pattern mode corresponding to a Karst geological backgrounds of the carbonate fractured-cave reservoirs is constructed; a well pattern injection production relation of the carbonate fractured-cave reservoirs is built and optimized. The method solves the problems that a conventional injection-production well pattern construction method is not applicable to development of the carbonate fractured-cave reservoirs and an existing irregular well pattern deployment method is not mature or referential. The new injection-production well pattern construction method suitable for the fractured-cave reservoirs is provided and improves the recovery efficiency of the fractured-cave reservoirs.

Description

technical field [0001] The invention relates to the technical field of oil and gas reservoir development, in particular to an injection-production well pattern construction method suitable for carbonate fracture-cavity reservoirs. Background technique [0002] The fractured-vuggy carbonate reservoirs in Tahe Oilfield are mainly composed of structural fractures generated by structural deformation and pores, caves, and fractures formed by karstification. The set space has various shapes, great disparities in size, uneven distribution, and strong heterogeneity. It is not only different from fractured carbonate reservoirs in the Middle East, but also from typical fractured-vuggy carbonate reservoirs in eastern China, and even more from conventional porous sandstone reservoirs. [0003] The current injection-production well pattern for fracture-vuggy reservoirs is based on the basic well pattern with large vugs as the main producing objects during the production capacity constru...

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Problems solved by technology

[0003] The current injection-production well pattern for fracture-vuggy reservoirs is based on the basic well pattern with large vugs as the main producing objects during the production capacity construction period, and the degree of control over small-scale fractures and vugs is relatively low. The unit is the object of development and management, but the size of fractures and caves in carbonate reservoirs is very different and the distribution is uneven. Therefore, the current injection-production well pattern of fracture-cavity reservoirs cannot be fully applied to carbonate reservoirs. ; At present, relatively mature ideas and methods for constructing injection-production well patterns have been formed in clastic rock reservoirs. The form and construction method of the injection-production well pattern of rock reservoirs are not suitable for carbonate rock reservoirs, because the regular well patterns (including row well pattern and area well pattern) of conventional clastic rock reservoirs have a great influence on The structural requirements are: the oil layer structure should be relatively complete, the oil layer distribution should be relatively stable, the position of the oil-bearing boundary should be clear, the internal and external connectivity should be good, and the flow coefficient should be high. In addition, the row and column well pattern is not suitable for the reservoir with serious heterogeneity. It leads to uneven advancement of the water line; the plane geometric relationship between oil and water wells in the areal well pattern has a great influence on the sweep coefficient of water injection, which requires a regular well pattern. Due to the qualitative and irregular nature, the construction method and pattern of regular well patterns are difficult to implement and poor in applicability

The deployment of irregular well patterns is mainly for the small oilfield area, irregular distribution of oil layers, and it is difficult to arrange regular water injection well patterns. For fractured-vuggy reservoirs with strong characteristics, how to consider different reservoir space types, fractured-vuggy structures and characteristics of injection-production relationship, optimal water injection methods, and well pattern forms, etc., and the deployment of irregular well patterns have no mature construction ideas that can be used for reference. and methods

[0004] It can be seen that there is currently no set of injection-production well pattern construction methods suitable for the characteristics of carbonate fracture-cavity reservoirs.

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