Study On Enhancing Water Flooding Effect For Low Permeability Reservoir In Fault Block Da 43 Of Yi Bei Oilfield

Fault block Da 43 of Yi Bei oilfield is located in Hekou District,Dongying,Shandong Province.And it's located in the Northeast of Yihezhuang Hump.The oil bearing sequences of this block are sand section 2 and sand section 4.Yi Bei oilfield is a structural lithologic reservoir with a complicated fault block.Although fault block Da 43 has relatively high producing reserves,it is unbalanced in its layers.A series of strata is employed and layers are separated to produce.Natural energy of this fault is not enough,and the current pressure is low.Daily fluid production of single oil well in Fault block Da 43 is low,with relatively high initial productivity and low current productivity.Current water content is not high and water injection effect is in good condition for normal water well.In order to improve the water flooding effect,geology investigation,developing situation and development characteristics were made for sand section 2 and sand section 4 in this block.Some problems still exist currently,namely(1)incomplete well pattern and relatively high uncontrolled reserves;(2)low block energy and high oil layer pressure drop;(3)bad well pattern adaptability and low injection-production corresponding rates.Basing on this,countermeasures are put forward :(1)complete the injection-production well pattern;(2)improve the injection capacity and supplement the formation energy.(3)adjust the injection-production relationship.Through distribution study of remaining oil in this block and water flooding mechanism,adjustment principles of the development plan are summed up to reduce uncontrolled reserves.Adjust injection-production relation and improve injection-production corresponding rate with the larger fault block as the main object of adjustment to complete injection-production well pattern.For the fault block of small oil-bearing and deposits,maintain the status quo of production in principle,supply energy timely in the future and carry out water-flood stuff and huff in single well.Through the optimization and demonstration of parameters in reservoir engineering.development methods,well pattern space and developing lays are decided.With principles of making full use of old wells and building new wells in remaining oil enrichment zone as well as incomplete well pattern zone,some new wells are built.Based on well location,the production allocation is calculated,and subsequent indexes are predicted.All of these lay a solid foundation to improve the water flooding effect of next step,in fault block Da 43.