| ABSTRACT:With the increasing pressure on energy, oil exploration drilling work encounter more and more deep and ultra deep wells in-depth, and complex geological environment also emerge in endlessly. Therefore, high temperature and high salt are the problems that drilling work have been facing always, also are the emphasis and difficult of drilling fluid research. At present, the commonly used drilling fluid filtrate-loss reducers are natural or synthetic polymers with relatively high molecular weight. They can reduce the filtration of drilling fluid, but also can increase drilling fluid viscosity in varying degrees at the same time, so the problems are caused that viscosity increased in high temperature and encountered pollution. Some filtrate-loss reducers with relatively small molecular weight can meet the needs in the use, although the cost of reducing the amount of filtrate more you use more, so gradually increased the cost of inputs.Drilling fluid filtrate-loss reducer of anti-temperature, anti-salt, low cost, extensive source and easy to industrialize becomes one of the much-needed drilling fluid treat agents. This article aims at the particular characteristic of nanomaterials, polymers are nanomodified by using inorganic nano-structured materials, therefore prepared series of polymer/inorganic nanocomposite filtrate-loss reducers. Their structure and properties were characterized, and studied the mechanism of their actions. This article has the following innovation:(1) Three kinds of nanocomposites of the P (AM/AMPS)/organic bentonite, P (AM /AA)/organic bentonite and P (AMPS/AM/AA)/organic bentonite were successfully prepared. FT-IR analysis showed that the monomers and bentonite occurred the grafting reaction; XRD analysis showed that the layer structure of bentonite was stripped with varying degrees or completely spread by the energy that generated in the polymerization of monomers and bentonite. SEM analysis further confirmed the results of XRD analysis. filtrate-loss performance test results show that the three kinds of nano composite materials have good effects on filtrate-loss and no increased viscosity at high temperature (200℃) and high salt concentration (36% saturated salt water).(2) The high temperature viscosity-loss filtrate-loss reducer, SiO2/SSMA nanocomposite, was Successfully prepared. its structure was characterized by FT-IR, XRD, SEM, its thermal stability was analyzed by TGA, and its performance was tested. The results showed that the diameter of the nano composite material was about 200 nm, and the thermal stability was better than SSMA's; the composite filtrate-loss reducer had a dual function of viscosity-loss and filtrate-loss at high temperature. The viscosity reduction rate was 81% at 200℃aging temperature when the usage of SiO2/SSMA nanocomposite was 0.5%. The filtration amounts of freshwater mud were reduced from 23mL to 8mL at 180℃aging temperature when the usage of SiO2/SSMA nanocomposite was 0.2%.(3)The humic acid modified polymer/Fe3+nanocomposite, high temperature viscosity-loss filtrate-loss reducer was successfully prepared. When the usage of this filtrate-loss reducer was 1.5%, and the the aging temperature was 200℃, the viscosity reduction rate was 89%, filtrate reduction was 8.5mL. A new filtrate-loss reducer with anti-temperature and salt was obtained by grafting reaction between humic acid modified polymer/Fe3+nano composite and acrylic silk waste, acrylic silk waste is one of industrial waste. The filtration reduction of saturated salt solution-based slurry was only 3.0mL at 180℃aging temperature When the usage of this novel product was 5%. The thickness of the mud cake was 0.60mm under the same conditions of temperature and usage.
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