| Guanidine glue is currently the most widely used thickener in fracturing and mining of oil wells,due to cheap and easy to get,the amount of residue is small,easy to degrade the advantages of environmental protection and continue to be developed research.With the deep well,ultra-deep well development,fracturing temperature is increasing,Developed with high temperature performance of the guanidine gel fracturing fluid more and more urgent.Modified guanidine and cross-linking agent is the main factor affecting the temperature resistance of guanidine gel fracturing fluid,both synergies,we can get a kind of network structure with good temperature and shear resistance of the gel fracturing fluid,but has not yet developed a real sense of the ultra-high temperature performance of modified guanidine cross-linked fracturing fluid.Therefore,the preparation of good performance modified guanidine and its cross-linking agent,it is very important to study the mechanism and applicability of fracturing fluid to the development of high temperature fracturing fluid system.In this paper,organic boron cross linking agent?BOC?,organic zirconium cross linking agent-p-p?ZOC-01?and organic boron-zirconium cross linking agent?BZC?were prepared by complex reaction.The modification of the guanidine gel by the functional group derivatization method was used to prepare the carboxymethyl hydroxypropyl guanidine?CMHPG-09?.BZC was synergistic with CMHPG-09,and stabilizer and breaker were added,Additives and other additives,to get a set of high temperature-resistant guanidine fracturing fluid system.Laboratory studies have shown that:?1?The final viscosity of BOC cross-linked HPG fracturing fluid was about200mPa·s at 160 ? and 170s-1 for 30 min.And the final viscosity of ZOC-01cross-linked HPG fracturing fluid was about 80mPa·s BZC at 160 ? and 170s-1 for30 min.The final viscosity of BZC cross-linked HPG fracturing fluid was about170mPa·s at 180 ? and 170s-1 for 40 min.Through the analysis of BZC performance,it is concluded that the cross linking agent has delayed cross linking property and good compatibility with the sulphated ammonium per sulfate.The cross-linking with CMHPG-09 exhibits excellent temperature resistance up to 180 ?.?2?The optimal synthesis process of CMHPG-09 was as follows: acetone asdispersant,alkalizing agent dosage 4.2%,alkalization time 15 min,nitrogen time 20 min,propylene oxide dosage 6%,and chloroacetic acid dosage 8%,reaction time 160 min.CMHPG-09 cross-linked BZC fracturing fluid was cut at 160 ? for 170s-1 for30 min and the final viscosity was about 240mPa·s.The weight loss rate at 300 ? was reduced by the thermo gravimetric analysis of CMHPG-09.With a good thermal stability.The use of the concentration of 0.2% or more,the aqueous solution viscosity to meet the needs of fracturing,insoluble content is low,when the concentration of 0.8%,insoluble content of 5%.?3?Through the study on the temperature and shear resistance of fracturing fluid system,a complete high temperature resistant guanidine fracturing fluid was obtained.Recipe: 0.6CMHPG-09+0.6% BZC?BOC: ZOC-01 = 0.2?+1% Temperature Stabilizer Sodium thiosulfate + 0.5% Dispenser CF-5A + 0.05% Fungicide formaldehyde,pH =11.The comprehensive performance evaluation of high temperature resistant guanidine fracturing fluid system shows that the fracturing fluid system is sheared at180 ? for 170 s-1for 2 h,the final viscosity of fracturing is about 100mPa·s,Cw is3.76×10-4m/???,in line with the filter performance standards,and the loss of small.When the amount of breaker is greater than or equal to 0.02%,the breaking time is less than 6h,the viscosity of the breaker is less than or equal to 3.482mPa·s,the residue is less than or equal to 580 mg / L,the surface tension of the supernatant is less than or equal to 28.52 mN / m.The average damage degree of the permeability of the system is20.7%,the damage is less,and the compatibility of the breaker and the formation water is good.?4?The microstructure,temperature,temperature and shear resistance and the cross linking mechanism of pH and high temperature resistant guanidine fracturing fluid were analyzed.Under the microstructure,the high temperature resistant guanidine fracturing fluid system was membrane Structure,the link is close,the broken network structure has the ability of repair.The system is more sensitive to the temperature,the process of cross-linking,the gradual release of low temperature cross linking factor,high temperature cross linking factor and ultra-high temperature cross linking factor,Delayed cross-linking and anti-shear effect.When pH is too large,easy to cause "crossed" phenomenon,fracturing fluid system cross-linked uneven,temperature and shear resistance decreased.?5?In the application,the high temperature resistant guanidine fracturing fluid system is tested by the Chuanqing Drilling and Underground Operation Company.The fracturing fluid has the same performance requirements and is suitable for 180 ?reservoir fracturing and has been put into use. |
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