Polymer Plastic Stability Of Factors

The polymer gel studied in this paper is three-dimensional network structure of the weak crosslinking system which is intermolecular crosslinking mainly and is supplemented intramolecular crosslinking.The formation and properties(especially stability)of the polymer gel are constrained mainly by the polymer nature,crosslinker type and crosslinked pattern,water saltness,active impurities,pH,temperature and other factors.Research from the stability of the polymer gel system,this paper carried out the following tasks;(1)The gelling performance of the polymer gel system is studied from the polymer type(PHPAM,AP-P4 and KYPAM-2),the molecular weight and degree of the hydrolysis,experimental results show that 30 days viscosity retention rate of the gel systems formed by KYPAM-2 in 60℃and 80℃with chromium acetate crosslinker,in 70℃and 90℃with the organic phenolic crosslinker is between 85% and 94%,and under the same conditions 30 days viscosity retention rate of the gel systems formed by AP-P4 is between 80% and 90%; the polymer gel formed by low degree of hydrolysis(15-25%)had good stability(30 days viscosity retention rate is between 90% and 94 %).(2)The chromium acetate,aluminum citrate,organic phenolic FQ and Cr³⁺+FQ compound crosslinking system are Studied,experimental results show that in suitable type and concentration of crosslinker, when polymer concentration is in the range of 1000-3000mg/L,the gel systems which have 1-7 days adjustable gelling time,strength 1000-9000mPa.s,90 days viscosity retention rate at over 80% can be formed,temperature and salt-resistant capacity of the organic phenolic crosslinldng system(100℃,70000mg/L)is stronger than chromium acetate,aluminum citrate (80℃,50000rag/L).(3)Through controlling on the addition reaction and the condensation reaction,the active phenolic resin crosslinker has been improved,and the RF crosslinker is obtained.Under the different concentrations,the gelling performance of RF with KYPAM-2, salinity,pH and temperature is taken into consideration,experimental results show that the gelling performance of the RF is better than organic phenolic,90 days viscosity retention rate can achieve 85%.(4)Selecting four good representative oilfield induced water,and the adaptability between polymer gel system and oilfield induced water is studied on the basis of the water quality analysis data.Guantao water has good quality,after deaeration,under the 60℃and 70℃three months viscosity retention rate of the systems when concentration of KYPAM-2 is 3000rag/L,polymer / chromium acetate ratio respectively is 5;1,8;1,10;1 is above 80%.In the Jilin Xinli Oilfield induced water the content of Fe²⁺,Fe³⁺,oxygen is low, TGB and SRB have higher levels,and containing Br^-,I^- and other trace elements, experimental results show that in the induced water with Br^-,I^-,gelling performance of the chromium acetate crosslinker is very poor,or even no gelling,aluminum citrate and organic phenolic crosslinking system have good gelling performance,using aluminum citrate erosslinker,after deaeration,sterilization with induced water,under 60℃three months viscosity retention rate of the systems when concentration of KYPAM-2 is 2000mg/L, polymer / aluminum citrate ratio respectively is 5;1,8;1,10;1 can achieve above 80%.The main active impuritiy in Nanyang Shuanghe Shuangliang induced water is H₂S,gelling performance of the RF crosslinker is well,selecting KYPAM-2 and AP-P4 polymer and RF crosslinker,when the polymer concentration is 3000mg/L and RF concentrations respectively is 0.6%,0.8%,under 80℃three months viscosity retention rate of the systems is about 82% and under 90℃is about 75%; In the induced water of the Dagang southern Oilfield,total salinity is high,and active impurities are complex,chromium acetate,aluminum citrate crosslinking system can not erosslink,gelling performance of RF crosslinker is well,when concentration of KYPAM-2 respectively is 2000,3000 mg/L,concentration of RF respectively is 0.6,0.8%,under 80℃three months viscosity retention rate of the system can achieve above 80%,and under 90℃can achieve above 72%.The results show;among PHPAM.AP-P4 and KYPAM-2,the resistance to temperature and salt of KYPAM-2 is better than others,and it can meet a wider range; improved RF crosslinker has higher resistance to temperature and salt,can further improve the temperature and salt-resistant of polymer; the effect of active impurities in the oilfield induced water on the polymer gel is very significant,through the corresponding treatment,gel performance can be further increased.The research results of' this paper have certain-spot guidance and practical application value.