| This paper summarized the details of injection well daily work, compares the difference of sand production between common wells and injection well and the difficulty during injection well fried sand chemical consolidation. Several common chemical sand consolidation ways are talked with their specilities,consolidate progress and theory and the difference between mechanical consolidation.In China,most oil well formation are loose sandstone, the cementation is weak and it is prone to product sand especially in injection well,in the water wells frequently injection and too high water pressure and speed causes the weak cementation disappear which making injection layer get stuck even plugged, then water injection couldn’t go. This program is trying to find an effective chemical way to solve the sand production in injection well, in comparison to common well consolidation, injection well needs more anti-eroding, anti-flushing, Hydrophilic performance. We do a lot of indoor experiment and finally preferred two kinds of resin system which could consolidate well under the100℃,one is modified furan resin FNl,the other is modified epoxy resin HYl.The sand is40～60mesh quartz sand, the curing agent of FN1system is salmak,HY1system curing agent is GN1,in preliminary experiments we ensure the best amount of the agent is FN1resin:salmak=5%:1.5%(according to the sand weight),HY1resin:GN1=6%:1.5%. And then we test the concretion performance,each of this two systems can consolidate well under60℃,and when the temperature is above100℃,the consolidation react become bad, the best consolidation time is between24-72h,the react is mainly happened in4-24h,after24h,the concretion become more hard with more time, but not too much. To accelerate the progress,the consolidate time is all24h,the best compressive strength of FN1,HY1is9.06Mpa,18.74Mpa.When the fried quartz sand is mixed up with water and200mesh clay dust, the compressive strength decrease, and FN1system couldn’t consolidate under these two condition,HYl system concretion get a higher compressive strength when the water content is lower than5%,active hydrogen ion in water helps to epoxy group open-loop, but its strength also decreases when water is high than5%,when clay dust content is20%,the HY1system concretion decrease to7.84Mpa.when the concretion is flushed by30ml/min,3Mpa water for48hours,the rate of sand production of FN1,HY1is0.48%,0.13%which are low. In soak experiment,HYl system is not compatible to oil such as diesel, kerosene. After soaking in diesel for30days, its compressive strength is14.46Mpa, saltwater permeability is963md. The last indoor test is concretion wettability test,which is tested by Harke wetting angle instrument,the test temperature is20℃, concretion wetting angle is compared to a hydrophilic mica flake. When water is dropped on FN1,HY1concretion and mica, the contact angle is44.3°,54.2°,28°,all concretion are water wet.After indoor sand stirring experiment,we use HY1system to do in-situ simulation experiment by HGS instrument which is designed and manufactured by Hanc new technology research institute. In simulation experment,HYl system can also consolidate well in60℃,but the concretion compressive strength goes to14.36Mpa,permeability to saltwater is963md,sand product rate after48hours water flush is0.31%. When swelling agent kerosene volume is4～5times to sand volume,the permeability to saltwater restores above2470md.When the amount of HY1agents is2.2～2.4times to the best amount, the concretion is fully plugged with a low permeability which is under78～200md.After all experiment including indoor sand stirring experiment and in-situ simulation experiment,We make sure that HY1system is a kind of good consolidation system for injection well sand prevention and cure. Its performance can meet up the standard level and could be popularized to more injection wells. |
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