Practice and Understanding of Fine Control Fracturing Technology for Three Types of Sandstone Reservoirs

Abstract

Development Zone B of Daqing Oilfield is located in the northwest of the oilfield structure and at the western end of the anticline structure in the north. The structure is relatively gentle. It belongs to sandstone reservoirs deposited by typical continental fluvial-delta facies reservoirs. There are many faults in this area, with a large fault distance. A total of 29 large and small faults are developed, all of which are normal faults. The faults have good sealing performance. The sand bodies in this area are cut into narrow strips by faults, with a small distribution area, and the phenomenon of one injection and one production or with and without injection is serious. The contradictions among and within the three types of reservoirs are prominent, and the degree of reservoir production is low. In order to study the high-efficiency tapping potential technology for the three types of reservoirs in pure oil region, technical research and experiments were carried out from 2017 to 2018. Through in-depth analysis of the main factors that affect the development effect of the three types of reservoirs in pure oil region, the technical research route with fine subdivision and large penetration ratio fracture sand control body to improve interlayer and plane contradictions as the research direction was determined, which is aimed at the difference of reservoir sand body development characteristics and injection-production connectivity in each direction, fine subdivision was carried out on the target layer in the longitudinal direction, and the reservoir sand body characteristics and injection-production relationship were combined in the plane. Fine control fracturing technology has been tried in three types of reservoirs, and initial results have been achieved. The fine control fracturing technology has been applied to two wells, with a fracturing efficiency of 100%, increasing oil production by 8.6t at the initial stage of a single well and 2186.3t at the stage. Field tests show that the fine control fracturing technology has a remarkable effect on the reconstruction and production of thin and poor reservoirs, and explores a new way to tap the potential of thin and poor reservoirs in the later period of ultra-high water cut.