METHOD FOR DIAGNOSING WATER DISCHARGED FROM GAS WELLS USING CHEMICAL ANALYSIS DATA Russian patent published in 1999 - IPC

FIELD: development of hydrocarbon deposits; gas industry. SUBSTANCE: method involves determination of general mineralization and chemical composition of extracted water. In addition, thermobarometer is used to measure operating parameters of gas well to calculate by its readings amount of condensed water in extracted gas W_cond; water samples are taken and subjected to chemical analysis for general mineralization M_i and content of basic ions Na⁺, K⁺, Ca⁺⁺ followed by calculation of Ca/(Na +K) ratio. Then proportion of stratal water in analyzed sample is found from expression C = 1 at Ca/(Na+K); C = 1.015 - 0.145 Ca/(Na + K) at Ca/(Na+K) ≤ 0,1 for 0,1 < Ca/(Na+K) < 7; C = 0, total amount of mineralized water Ca/(Na+K) > 7 is calculated from formula W_min and total amount of water discharged from well W_min= (W_cond•M_i)/(C+M_st+(1-C)•M_t-M_i, including condensed water, from formula W_dis, where M_dis= (C•W_min•M_st+(1-C)•W_min•M_t/M_i) is, respectively, stratal and technogenous water. After that, amount of stratal and technogenous water M_st, M_t and M_st= C•W_min и W_t= (1-C)W_min, respectively, discharged from well is found from formulas W_st and W_t. EFFECT: facilitated determination of proportion of condensed, technogenous, and stratal water in liquid discharged together with extracted gas.