METHOD OF DETECTING LOCATION OF OLD WATER-OIL CONTACTS IN PRODUCING CARBONATE FORMATIONS Russian patent published in 2000 - IPC

FIELD: oil-and-gas producing industry. SUBSTANCE: method includes well drilling; recovery of core material; specimen preparing; X-ray investigation of structure of specimen; determination of degree of perfection of calcite structure with consideration of sizes of its blocks of coherent dissemination. It is believed that change of perfection degree of calcite crystalline structure from 0.18 to 0.75 and sizes of blocks of coherent dissemination from 324 to 130 nm correspond to subzone of cementation of old water-oil contacts, and change of perfection degree from 2.5 to 4.5 and sizes of blocks of coherent dissemination from 90 to 67 nm correspond to subzone of dispersion of old water-oil contacts of producing carbonate formation located direct above subzone of cementation contacting with it and interpreted in common as old water-oil contacts. EFFECT: higher reliability, efficiency and accuracy in detection of location of old water-oil contacts in producing carbonate formations. 2 dwg, 4 ex