PROCEDURE FOR DETECTION OF PRESSURE FLUCTUATIONS IN RESERVOIR, SYSTEM FOR ITS IMPLEMENTATION, PROCEDURE FOR ANALYSIS OF FLUID PRESSURE FLUCTUATIONS INSIDE RESERVOIR Russian patent published in 2011 - IPC E21B47/00 E21B49/10 

FIELD: oil and gas production.

SUBSTANCE: downhole tool containing first probe is located in first position and second probe is located in second position removed from first one inside well. Pressure data are received with the second probe at a closed isolation valve connecting the second probe with a straight-through pipeline of the tool. Sampling and fluid analysis are performed in a well by means of the first probe. Presence of the first phase of fluid is detected inside the tool. There are detected pressure fluctuations inside the reservoir by means of the second probe. The second phase of fluid is identified on base of detected pressure fluctuations. The system for implementation of the procedure for detection of pressure fluctuations in a reservoir is equipped with the first probe, the second probe, a module for fluid analysis, with a cable and a controller. The first probe is connected with a case in the first position and is designed for sampling operations. The second probe is connected with the case in the second position removed from the first one and is designed for obtaining data on pressure at a closed isolation valve connecting the second probe with the straight-through pipeline of the tool. The controller connected with the probes controls the sampling operation by means of the first probe for analysis of the first phase of fluid. Also, the controller is designed for control of detection of pressure fluctuation inside the reservoir by means of the second probe and for detection of the second phase of fluid on base of detection of pressure fluctuations.

EFFECT: upgraded accuracy of determination of phase transition in reservoir.

31 cl, 13 dwg