High Temperature Preparation Of Fracturing Fluid Thickener System Performance Evaluation

A reservoir for the western region (formation temperature is 110℃) high temperature characteristics, combined with the formation fluid characteristics, high temperature fracturing fluid system carried out the research. Since conventional fracturing fluid systems heated at high temperatures, shear viscosity decreases too fast, can not meet the requirements of high temperature deep fracturing, Based on the formula of the main fracturing fluid performance evaluation of reagents and a group of selected new high temperature fracturing fluid system.In this process, the first synthesis of a modified guar CMGG, by IR and chemical titration test group were the introduction and distribution, and with the other two thickener thickening capacity, water insoluble, resistant to temperature and shear resistance properties were compared, results showed that:the characteristics of thickening agent CMGG is less amount of water insoluble matter content is low, and better shear resistance temperature,110℃when the amount of thickening agent only 0.4%, shear viscosity after 1 hour or more to achieve 100mPa.s; gelation according to the speed of cross-linking agent, cross-linked and shear stability of the thermal stability of the evaluation, optimization of the BCL-organic boron crosslinker 61, identified the BCL-61 and CMGG compound ratio is between 1:3-3: 8, can effectively improve the fracturing fluid gel viscoelasticity and shear performance and reduce injury fracturing fluid residue;In addition, the use of capsule breaker NBA-101, the process can ensure that sand fracturing fluid viscosity, an effective solution to the fracturing fluid viscosity gel carrying sand to maintain the conflict and rapid gel breaking, after the success in creating joint so rapid gel breaking fracturing fluid flowback to reduce the damage to the reservoir fracturing fluid; use was 0.2%cleanup additive YBZP-2 by the surface tension of water at 72.8mN/m down to 25.38mN/m, YBZP-2 kerosene solution and interfacial tension values from dehydration 30.2mN/m down to 1.24 mN/m; 110℃and 1%when the HCY-2, filtration coefficient from 4.12×10-4 m/(?)reduced to 2.54×10-4 m/(?) reducing the rate of core damage.Selected a group of well fracturing fluid additive, the overall performance of the system was evaluated by a conclusion:When the temperature reaches 110℃, the thickening agent concentration of 0.37%of the base fluid viscosity 35.7mPa. s, and after cross-linking after 110℃,170s-1 under shear viscosity is still 50mPa.s 1 hour or more, the system heat resistance, gel breaking performance, fluid loss performance than the conventional fracturing fluids Department at 110℃in the performance of high temperature stability, good compatibility, significantly increased in temperature, shear resistance at the same time, there is no increase on the formation permeability damage to the fracturing process has been significantly expanded the scope of application.