Research On Anti-high Temperature Environmental Protection Drilling Fluid Treatment Agent And System

In this paper,high temperature resistant and environmental friendly drilling fluid treatment agents are studied with low viscosity,low filtration loss,high shear and high temperature resistance as the research objectives.Three kinds of anti-high temperature environmental protection materials,namely multi-metal hydroxide precipitation（M-MMH）,multi-metal orthoelectric gum and XH gum powder,were studied and a set of drilling fluid system was formed.M-MMH,multi-metal orthoelectric gum,and XH gum powder were synthesized indoors,and their physicochemical properties were analyzed,and their conclusions are as follows.（1）Inorganic-type anti-high-temperature drilling fluid inhibitors were used as research objects,and indoor experiments were determined to prepare zinc（Cu,Fe）doped multi-metal hydroxide precipitation（M-MMH）samples.Mg Cl₂,Al Cl₃,Fe Cl₃,Cu Cl₂ and Zn Cl₂ were used as raw materials,and M-MMH samples with different molar ratios were synthesized by co-precipitation method.The inhibition performance of the synthesized M-MMH samples at room temperature and high temperature was evaluated by linear expansion experiment,anti-expansion experiment and mud ball experiment,and the products with the best inhibition performance and their optimal concentrations were determined in the experiments;by X-ray diffraction The crystal structure of the synthesized M-MMH gum samples was analyzed by X-ray diffraction,SEM and TEM;the mechanism of inhibition performance of the synthesized M-MMH samples was analyzed by laser particle size test,zeta potential test and thermogravimetric test;the samples were directly used as drilling fluid base slurry to evaluate the rheological properties at room temperature and 200℃.The linear swelling experiment,anti-swelling experiment and mud ball experiment showed that the synthesized M-MMH samples have strong inhibiting ability to the hydration swelling and hydration dispersion of clay at room temperature;the experimental results showed that the 2-hour linear swelling rate of 4%M6-Fe was only 12.32%at room temperature,the anti-swelling rate was 81.16%at room temperature,and the linear swelling rate was 20.28%at 90℃,indicating that it has strong inhibiting ability at room temperature and high temperature.The 4%M6-Fe exhibits low viscosity,high kinetoplastic ratio and high temperature resistance,and its apparent viscosity retention rate reaches 100%at 200℃for 16h of hot rolling,with kinetoplastic ratio of 2.33.（2）To solve the problem of dispersion and stability of M-MMH and to synthesize samples that can replace bentonite as the base slurry based on M-MMH.Weakly alkaline Na₂CO3,Na₂Si O₃,and C₁₇H₃₃CO₂Na are considered as precipitating agents to form nanoscale multi-metal positively charged gels with large layer spacing and small particle size.In this chapter,the molar ratio of metals（Mg:Al:Fe=3:1:1）determined in Chapter 2 was used to synthesize the multi-metal orthoelectric colloid at room temperature by co-precipitation method,and it was found that the 4%S2 synthesized by Na₂Si O₃ has low viscosity,low filtration loss and high dynamic-plastic ratio at room temperature for drilling fluid base slurry,which fully meets the field requirements.After aging at 250℃for 16 h,it maintains its excellent characteristics.X-ray diffraction and infrared spectroscopy experiments showed that S2 has the most complete crystal structure with large interlayer distance and strong ion exchange ability.Thermogravimetric experiments show that S2 is crystal stable and its crystal temperature resistance can reach 340℃.zeta potential experiments,particle size analysis experiments,SEM and TEM experiments show that S2 is a nanomaterial with complete morphology and uniform distribution.Finally,the addition of anionic surfactant improved the filtration loss of S2 as a base slurry,when 4%S2+0.4%SAS reduced the filtration loss from 45.6 m L to 15.4 m L and increased the kinetic-plastic ratio to 2.16,and reduced the overall viscosity of the drilling fluid,which is consistent with the characteristics of low viscosity,low filtration loss and high kinetic-plastic ratio,and meets the conditions for carrying out field applications.（3）A drilling fluid formulation with low viscosity,high shear,high kinetoplastic ratio and high temperature resistance was formulated using XH colloidal powder as a filter loss reduction agent.The preparation of XH gum powder and the evaluation of drilling fluid performance at room temperature were introduced,and the temperature resistance limits of XH gum powder,tapioca starch,potato starch and corn starch were tested.The rheology of the drilling fluid formulation was also confirmed for the amount of tapioca starch added,and the best rheology was obtained at 2%addition.In order to increase the cutting power and kinetic-plastic ratio of the formulation,the addition of orthoelectric gum,xanthan gum and polyacrylamide to the drilling fluid formulation was tried,and the experimental results showed that at 180℃,the orthoelectric gum had the best cutting lifting performance with a kinetic-plastic ratio of 2.11.The lubricants of the formulation were also preferentially selected,and three lubricants,graphite,mica and locust glycolipid,were investigated,and it was found that at 180℃,only mica was the best in ensuring The lubricity of the drilling fluid was improved under the premise of rheology and environmental friendliness of the drilling fluid formulation.In order to improve the overall temperature resistance limit of the formulation to 200°C,an attempt was made to add humic acid,tannin and potassium silicate to the formulation,and the experimental results showed that the addition of tannin led to a temperature resistance of 200°C.Infrared characterization experiments were conducted on XH gum powder,which revealed the presence of a large number of temperature-resistant chemical bonds.The final formulation of the environmentally friendly drilling fluid resistant to 200℃was:4%base slurry+1%XH gum powder+2%tapioca starch+1%orthoelectric gum+0.5%mica+1%humic acid.