Research On Cationic Polymer Inhibitor

With the increasing development of world energy demand and drilling technology,drilling depth is increasing,drilled formation becomes more and more complicated,shale wellbore stability problems often course problems.The safety,quality,fast and efficient drilling is becoming more difficult,the drilling fluid technology put forward more comprehensive requirements.The role of shale inhibitor in reservoir protection is to prevent the hydration swelling and dispersion of clay minerals in the reservoir,to improve the conditions of the seepage channel,so as to effectively prevent the reduction of permeability and ensure the production of oil wells.Therefore,it is of great significance to study the shale inhibitor with good performance and adaptability.At present,more and more kinds of shale inhibitors are cationic polymer inhibitors.Study on cationic polymer has been more common,but the domestic study on cationic polymers are relatively less,for the study of shale inhibitor,is the most limited to cationic polyacrylamide reports,complex process and high cost,the effect is not ideal,so for a wide source of raw materials,to explore the structure and properties of relations with the new single synthesis of a new cationic polymer has a profound theoretical significance and broad application prospect.Using AM,DMDAAC,KH-570 three kinds of monomer synthesis experiment,through orthogonal experiment,we find out the condition of the reaction to get the final synthesis of a cationic polymer inhibitor,the product named MCH-511.The experimental results show that MCH-511 has good inhibition,and has little influence on the rheological property of the drilling fluid system,and it can resist high temperature up to 160 centigrade.Through optimizing the fluid loss agent,tackifier,inhibitor and lubricant additives preferably,we establish a cationic polymer drilling fluid system,the drilling fluid formula is:4%slurry+1%MCH-511+0.6%PAM+0.2%XC+2%LV-PAC+1%SPNH+2.0%HL-8.The optimized drilling fluid system has the advantages of excellent temperature resistance,lubricity,inhibition performance,plugging performance,anti pollution ability and protection of oil and gas bearing capacity.The system of the drilling fluid system can resist the temperature of 160℃,the friction coefficient was 0.24,anti NaCl pollution can reach 10%,CaCl₂ 1%,MgCl₂ 0.5%,anti pollution ability of drilling cuttings is up to 10%;the invasion depth of small sand bed and with good sealing performance.