METHOD OF EVALUATION OF WATER CUTTINGS OF WELL PRODUCTION OF OIL WELLS "ОХН+" Russian patent published in 2008 - IPC E21B47/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil extraction and can be employed for operational registration of yields of oil and gas condensate wells in systems of pressure sealed gathering. Partially separated production of well contained in a vertical cylinder vessel (VCV) is held till complete disappearance of gas bubbles and foam sedimentation; then the height of column of liquid (HLC) and hydro-static pressure (HSP) are measured. On base of obtained data liquid density is calculated and then mass water cut is determined using density values of water and oil containing in well production. Liquid contained in VCV, for instance in a reservoir of a level meter, is subject for example to sedimentation or chemical reagent treatment and heating to a condition of not complete disintegration into oil and water. Further as far as this vessel is emptying, continuous measurement of HSP and HLC is performed. On the character of dependence of HSP from HLC there determined density of water and oil in composition of liquid and also determined its volume water cut. If flow of liquid is uniform, then volume water cut is assessed on the character of dependence of HSP on time . To calculate density of water and oil in composition of liquid, dependence of HSP on HLC is graphed at its flowing off from VCV. Then upper and lower linear sections are found on the graph and density of water and oil correspondingly are calculated within the limits of these sections. The density of water is calculated within the limits of upper linear section by means of correlation of difference of HSP in two maximum remote from each other points and corresponding to its difference part of HLC. The density of oil is calculated within the limits of the lower linear section by means of correlation of HSP at any point of the lower linear section and corresponding to it HSP of measured HLC. In case of not complete disintegration of liquid into oil and water, revealed upper and lower linear sections are interpolated till crossing one another and for the following actions the received interpolated graph is taken as adequate to the one which would be received at complete disintegration of liquid to oil and water. To calculate volume water cut of liquid, if flowing out is uniform, dependence of HSP of liquid dependence on time is graphed, further upper and lower linear sections are found on this graph. At that volume water cut of liquid is determined on position of connecting point of upper and lower linear sections as ratio of time interval corresponding to the upper linear section to total time of liquid flowing off VCV.

EFFECT: upgraded accuracy of evaluation of water cut.

5 cl, 3 dwg