METHOD OF DETERMINING QUANTITY OF REAGENTS FOR TREATMENT OF DRILLING MUD Russian patent published in 1999 - IPC

FIELD: drilling of oil and gas wells; applicable in improvement of drilling muds for use in drilling-in oil-bearing producing formations. SUBSTANCE: method includes taking drillings (core) and mud samples; determination of content of organic colloid ΣC_pK_p, porosity, permeability of producing formation, actual surface tension of mud filtrate. Required value of surface tension is determined by specified mathematical expression. Then subject to determination are required temperature parameters of filtration ensuring exclusion of pipe sticking, and required filtration radius in producing formation. Content of stabilizing reagent is determined by mathematical dependence with consideration of minimum value of temperature parameter of filtration. With , drilling mud is additionally treated with stabilizing reagent in calculated quantity. Surfactant is added to drilling mud in quantity determined as sum of quantity of surfactant found in filtrate of drilling mud and quantity of surfactant adsorbed on sold phase of drilling mud. EFFECT: preserved reservoir properties and higher productivity of formation. 1 tbl