| Profile control and water shutoff technology is one of the effective methods to stabilize production and control water cut for water flooding development reservoir. Polymer gel plays a very important role in improving water injection profile and enhancing sweep efficiency.This paper focused on high temperature and salinity Channel sand reservoir and developed a kind of gel through laboratory experiments. Physical simulation experiments were carried out to study injection performance, sealing performance, profile improved performance and profile control effect of the gel system. In addition, we designed the profile modification construction parameter about Y well group. Mainly research contents completed are as followed:(1) The article filtered the temperature resistance and salt tolerance polymer AN125SH after evaluating five kinds of polymer's thermal-endurance, salt-resistance, shear-resistance and gelling properties. The performance of the gel which crosslinked by polymer with FQ-1 was excellent.(2) The influences of polymer type and its concentration, crosslinker type and its concentration, stabilizer, salinity, temperature and pH value upon the gelling properties were investigated. The appropriate composition of gel formula as followed:the AN125SH concentration was between 0.6% and 0.8%, the FQ-1 concentration ranging from 0.8%to 1% and the stabilizer concentration ranging from 50mg/L to 100mg/L. The gel prepared with a salinity of 5.6×104 mg/L had good thermal stability with gel time ranging from 72h to 80h and gel strength from 5.3Pa to 9.6Pa under 110?.(3) Core flow experiments were carried out to evaluate dynamic performance about gel. The gel showed better injection performance in high permeability cores and the injectivity became worse with the decrease of the core permeability. The gel showed stronger plugging strength in different permeability cores, residual resistance factor and plugging rate was 43.83 and 97.71%respectively. The double-core flow experiments showed that the gel prefered enter into high permeability core and the profile control effect was more obvious with the increase of the permeability ratio.(4) Effect factors of profile modification were researched by sand-packed model.?The profile control effect at water cut 60% was much better than that of 90%, the higher the residual oil saturationthe is, the greater the displacement efficiency is;?Interlayer position could affect the oil displacement result. When interlayer lied between low and high permeability layer, interlayer prevented water from longitudinal flow which promote water flooding low permeability layer. The displacement efficiency was higher with the extension of interlayer length; When interlayer lied between high and medium permeability layer, the interlayer prevented water from flooding medium permeability layer which made the worse water displacement effects;?Interlayer and gel could adjust the water injection profile simultaneously, the subsequent oil displacement effect was better with the increase of remaining oil;?The profile control effect of gel and microgel alternate injection was better than that single injection. Gel plugging high permeable layer combined with microgel controlling profile deeply could increase the subsequent oil displacement efficiency significantly.(5) In order to improve water displacement effect in the Y well group of Channel sand reservoir, moderate profile plug, dosage, construction pressure and injection rate were proposed on the basis of laboratory research and production performance. |
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