Study And Application Of Crosslinked Polymers On Song Fangtun Oil-field

At present,most of oilfields step into the period of high and super high water cut,so it has to get much more important work to accurately interpreting oil saturation.That decrease the oil production rate.The phenomenon is especially severe and will affect holistic development effect.Aiming at this problem,polymer gel can be applied to block preferential path because of the rise of water absorption,and improve conformance factor,and control injection profile,finally,improve waterflood efficiency.This article carries out comprehensive technique research of water control and oil increment according to the Song fantun oil-field has high water and small oil layer.It aimed at the problem that exists in the synthesized and performance evaluation methods aspect of the low-temperature gel system?DWJ?.We proceed all sided and systemic research into the property of Cr³⁺cross-linked polymer gel making use of the indoor experiment method.The dynamic forecasted research was done by the numeric simulation method.The profile modification agent with the numeric simulation method was verified.The depth profile modification operation was done in the tested regions.It can obtain better effect and economic benefit.The low-temperature gel system in the paper crosslinked with chromium acetate that is compounded with some adjuvant,stabilizer and fungicide.The influences of various factors on the conventional performances of the polymer gel were designed with single factor method and orthogonal experiment method.The factors have the type of polymer?molecular weight and hydrolyzing degree?and its concentration,the mass ratio of polymer and cross-linker,salinity,adjuvant,fungicide and stabilizer etc.Finally,we have a better compatibility with the injected water in the field.The basic formulation decided as follows:HPAM?molecular weight of 24 million and hydrolyzing degree of 25%?which concentration is between 2000 mg/L to 3000 mg/L,the mass ratio of polymer and crosslinker is ranging from 8:1 to 10:1,the salinity is lower than 1%.the concentration of adjuvant?Oxalic Acid?is smaller than 100 mg/L,the fungicide?Formaldehyde?and the concentration of stabilizer are all lower than 80 mg/L.It is a good compatibility with oilfield sewage.In addition,we also a lot of experiments on the other performances for example the relationship of microstructure and gel strength,resistance coefficient,the viscoelasticity,residual resistance factor,displacement efficiency and the effect of profile modification by several techniques such as environmental scanning electron microscope?ESME?,HAAKE Rotational Rheometer and some core flow test.On the basis of laboratory,the system has been applied to the tested regions in Songfantun field.The result of numerical simulation shows that the low-temperature gel system improved 9 percent than the water driving the oil and 3 percent than the polymer driving the oil.