Study On Synthesizing High Temperature Drilling Fluid Viscosity

In order to increase drilling speed, we must reduce the drilling fluid viscosity, to improve the drilling fluid rheology. Add chemical viscosity reducer is to reduce the effective ways of drilling fluid viscosity. With the increasing depth of drilling, formation temperature getting higher and higher, the increase requested by the agent has an excellent anti-temperature, to ensure that the drilling fluid, stable performance, drilling carried out smoothly.The laboratory synthesis of the SSHIA copolymer is presented.After the designing of the molecular structure of high-temperature polymer,we use the BPO and the AIBN as the initiator,N,N-dimethylformamide as the solvent.When the BPO is taken,the copolymerization temperature is 85℃,the reaction time is 4h, the proportion of the itaconic acid and styrene is 1:1.2 and the amount of the initiator is 0.6%;When the AIBN is taken,the copolymerization temperature is 90℃,the reaction time is 5h, the proportion of the itaconic acid and styrene is 1:1.2 and the amount of the initiator is 1.0%. Then the styrene-itaconic acid copolymer is prepared and the chemical composition is identified by its IR-spectrum.The copolymer and 20 percent of the amount of concentrated sulphuric acid react at 50℃in 2 hrs to give a sulfonated styrene/itaconic acid copolymer—viscosity reducer for water base drilling fluids SSHIA.We add 0.3% viscosity reducer to the simulation of fluid,afterwards we find the apparent viscosity of the group of BPO drops 107mPa·s to 48mPa·s with the rate of 55.14%,while the apparent viscosity of the group of AIBN drops 107mPa·s to 56mPa·s with the rate of 52.28%;Dealing with the simulation of fluid under the high-temperature aging in 260℃for 16h,we aslo find the apparent viscosity of the group of BPO drops 59mPa·s to 27mPa·s with the rate of 45.76%,while the apparent viscosity of the group of AIBN drops 59mPa·s to 25mPa·s with the rate of 42.52%.The experimental data above shows that this product has good thermal stability.Experimental results show that pH value has little effect on the viscosity reducer. The viscosity reducer is applicable to a wide range(7~14) of pH values.