Determination of the dependence of the filtration properties of a biopolymer system on pressure, temperature and concentration of components

The object of study is the biopolymer system “X”, which is used as a clay-free drilling fluid for development of productive horizons. Biopolymer system “X” is a clay-free drilling fluid for drilling directional and horizontal wells, development of productive horizons under high pressures and temperatures. A distinctive feature of the biopolymer system is a high level of mineralization, increased heat resistance and high density, which significantly expands the scope of clay-free muds. At the same time, this system has a number of significant advantages: – high level of mineralization; – increased heat resistance (operable up to 150 °C); – high density, which expands the scope of application; – provides a higher coefficient of recovery of reservoir permeability compared to traditional weighted solutions; – low content of colloidal particles, which reduces the risk of deterioration of reservoir performance; – ability to control filtration properties at high temperatures and pressures. The following disadvantages can be identified based on the research: Significant increase in the filtration rate with increasing temperature (nonlinear dependence with a correlation coefficient of 0.773). 2. The need to maintain a constant concentration of potassium chloride (~3 %) to ensure the development quality of productive formations. Difficulty in controlling the properties due to the need to accurately select the concentrations of various components (sodium chloride and organomineral colmatant). The optimal ratio of components to ensure the stability of the system at temperatures up to 150 °C was obtained: sodium chloride concentration 15–20 %, stabilizer 0.75–1 %. This is due to the fact that the proposed composition has a number of features of synergistic interaction of the components, in particular the formation of stable complexes between biopolymers and sodium ions, which prevents the thermal destruction of polymer chains at high temperatures. At the same time, the stabilizer forms an additional protective layer around the polymer molecules, ensuring their resistance to oxidation and hydrolysis under high pressure of up to 7 MPa. The obtained research results indicate the possibility of effective use of the biopolymer system at high temperatures and pressures due to the thermostabilizing effect of sodium chloride and organo-mineral colmatant.