An Experimental Study On EOR Method By Gas Imbibition

Jidong oilfield mainly in Sanpu Sag region is located in the east part of Hebei province.Jidong oilfield is an offshore oil field.Nanpu Sag region consist of 10 sets of oil-bearing of shallow layer: Nm,Ng,Ed1,Ed2+3,Mid Deep layer: Es1,Es31,Es35,Es32+3,and Deep layer: J,O.Jidong oil field have 25 blocks where 5 oil fields are put into development,12 blocks is located in Nanpu land and 13 blocks in Nanpu oilfield.Jidong oilfield development in 3 layers,Shallow layer: high porosity(20-37%)and high permeability(100-2328 mD),developed mainly by natural energy.Mid Deep and Deep layer: low permeability(0.5-100 mD)and porosity(5-24),developed by water injection.Reservoir and production data from Jidong oilfield are proven oil reserves 732.58 Mtons,recoverable reserves 45.585 Mtons,Natural gas production 106 Mtons,and oil production 230.410 Mtons.This experiment used 9 core Jidong oilfield with variations in porosity and permeability values.Porosity and permeability of the core used in the experiment obtained from the laboratory.Permeability measurements performed by flowing gas into the core.Jidong oilfield core have porosity values is 5-37% and permeability values is 0.5-2328 mD.Core Jidong oilfield used in the experiment has a porosity values ranged between 7.55-25.38% and permeability values ranged between 0.16-171.8 mD.The experiment was carried out to compare the water injection water permeability and gas,and kerosene are used for oil injection.G3-4 gives the greatest recovery factor prior to the injection of nitrogen is 48.09% with 24.67 mD permeability and porosity 13.41%.Incremental recovery increase by nitrogen injection occurs in three cores,there are J24,J25 and S30,with the range of permeabilityin 0.16-171.8 mD and porosity in the range of 12%-16.56% provides good results when injected nitrogen at 0.1 PV injection.