关键词: 老井取心, 小曲率取心, 柔性模块化, 原位保真, 连续取心, 智能控制

Abstract: As the oilfield enters the middle and late periods of development, in order to identify the distribution characteristics, laws and main control factors of remaining oil, low-cost and high-efficiency in-situ coring has become an urgent technical barrier to overcome. This paper proposes a set of low-cost and high-efficiency design concepts concerning the sealed and continuous coring equipment for small-curvature horizontal wells. The coring tool uses the functional module as a unit, adopts a chain connection mode, and introduces an anti-lift module based on resetting soluble ball. Further using a linked system of ball valve independently controlled by pneumatic cylinder, it realizes the orderly opening and closing of the thermal-insulating and pressure-preservation sealed coring. On this basis, this paper proposes that the mechanism of forming membrane by cross-linking and solidification reaction should be applied to the core package; it satisfies the functions of “pressure maintaining, heat preservation and quality guaranteeing”, realizes the construction of the coring barrel environment under in-situ reservoir conditions, and breaks through the technical bottleneck problems such as high cost of coring, low coring efficiency, and the failure of coring samples to represent the physical properties of the reservoir rock mass, providing material conditions for the establishment of big data-driven digital twin core laboratories.

Key words: coring from old wells, small curvature coring, flexible modularity, in-situ fidelity, continuous coring, intelligent control