关键词: 超低渗透油藏, 水平井, 线注线采, 能量补充

Abstract: The “injection-on-points for areal production” method was used for the horizontal wells of the ultra-low permeability oil reservoirs in Ordos Basin. However, the horizontal wells under the five-point well pattern water injection development came across some problems, such as low efficiency and rapid declining. To enhance water injection for a higher water drive efficiency, the “line injection and line production” energy supplement technology for horizontal wells was proposed at the attempt to bring about inter-well mutual flooding, self-flooding between fractures and in-the-well imbibition. Based on the reservoir rock mechanical test, the fracture-network distribution prediction model was established to indicate the state of fractured seams under the different brittleness indexes and poor stress. The closer the brittleness is to 0.5 and the greater the two-way stress difference is, while the length-width ratio of the fractural belt is higher, flatter and more suitable to meet the requirements for line injection and line production. The Chang 63 oil reservoir of Heshui Oilfield was brought under fine geological study. The southern part of Z288 Well was selected as the experiment zone. The relative technological policies for well spacing, interval spacing, horizontal spacing and water-injection volume were formulated according to the fractural shape and reservoir characteristics. The well group test in Heshui area of the basin indicated that the single-well declining was reduced by 6.5 percent, confirming reasonability and operability of this method. Therefore, the technological method is effective to provide energy supplement for horizontal wells of ultra-low permeability oil reservoirs.