Improving Oil Recovery for Loose Gravel Sand Reservoirs with Large Bottom-water in Combination with Horizontal Wells and Vertical Wells

The 2nd member of Guantao Formation in Block Dalujia Lin 2of Neogene was a typical loose gravel sand reservoir with large bottom water.Its bottom water energy was abnormally enough,the bottom water coning was serious and water cut rose rapidly.For controlling the bottom water coning,raising of water cut and improving oil production and oil recovery,the well pattern of horizontal wells combined with vertical wells is used.The significant effects are obtained,oil recovery percent exceeds 35.4%,the predicted oil recovery is more than 44.1%.It has been high efficiently developed for 40years.It provides reference for the development of similar reservoirs.