Abstract: For determining a water cut of an oil-water mixture produced from an oil well at least one Venturi tube is placed in a well, through which an oil-water mixture, produced from a selected well segment, enters the borehole. During production process, pressure at a Venturi tube inlet and in a Venturi tube throat are measured, and flow temperature of the produced oil-water mixture at the Venturi tube inlet and the temperature of the Venturi tube wall in the Venturi tube throat are measured. Based on the results of the pressure and temperature measurements, the water cut of the oil-water mixture produced from the selected well segment is determined.

Abstract: A bottomhole temperature and a bottomhole pressure in a well are measured by means of sensors mounted on a perforation string below all perforation intervals. The measurements are made prior to perforating the well and after perforating the well until a temperature of a produced fluid returns to an initial reservoir temperature. Then the temperature of the produced fluid is measured by means of temperature sensors mounted on the perforation string above each perforation interval and a total production rate of the well is estimated. An excessive thermal energy of the produced fluid is calculated for each temperature sensor mounted on the perforation string above the perforation intervals and production rates of the individual perforation intervals are determined based on the calculated excessive thermal energies of the produced fluid and the known number of perforating charges in each perforation interval.

Abstract: A casing with temperature sensors attached to its outer surface is lowered into a borehole and a cement slurry is injected into an annulus between the casing and a borehole wall. During injecting and hardening of the cement temperature is measured and thermal conductivity of the rock formation surrounding the borehole is determined.

Abstract: Method for preheating an oil reservoir comprises injecting saturated or superheated steam at an initial injection pressure into a tubing placed inside a well drilled in the oil reservoir. Steam temperature at an outlet of the tubing is measured and a heat flow from the well to the oil reservoir is calculated. An optimal steam injection rate when steam quality of the injected steam at the tubing outlet becomes greater than zero, is calculated, the optimal steam injection rate ensuring compensation of the heat flow from the well to the oil reservoir with the heat of steam condensation. A steam injection rate is decreased to the calculated optimal steam injection rate value by decreasing the initial injection pressure providing constant temperature at the outlet of the tubing.

Abstract: A method for the determination of an inflow profile and bottom-hole area parameters (perforation zone parameters, bottom-hole area pollution parameters) in a multipay well comprises changing a production rate and measuring a temperature of a fluid flowing into the well as a function of time for each pay zone. Then a derivative of this temperature with respect to a logarithm of a time passed after the well production rate has been changed for each pay zone is determined. An inflow profile and other parameters are calculated based on a value of said derivative when it becomes constant and on a time after which the value of the derivative becomes constant.

Abstract: A pressure in a wellbore and a temperature at least at one point of the wellbore are measured during wellbore testing. Transient profiles of temperature along the wellbore are determined and changes in a density of a downhole fluid and in a length of atubing when the wellbore is shut in are calculated. The pressure measurement results are corrected on the basis of the calculated changes in the density of the downhole fluid and in the length of the tubing.

Abstract: Temperature is measured in a shut-in wellbore and rates of temperature change in depth intervals within productive layers and in depth intervals adjacent to the productive layers are determined. Areas are selected in the depth intervals within the productive layers wherein the rate of temperature change is significantly higher than the rate of change in the depth intervals adjacent to the productive layers. A numerical model of temperature change in the shut-in wellbore is created taking into account a filtration effect of a reservoir fluid on the rate of the temperature change in the shut-in wellbore. The measurement results are compared with the numerical modeling results, and their best match is used for determining a fluid filtration velocity in the selected areas in the depth intervals within the productive layers.

Abstract: Methods for determining an inflow profile of multilayer reservoir fluids in a wellbore are described herein. A bottom-hole zone is cooled before well perforation. Then, the wellbore is perforated, and a flow temperature is measured in the wellbore above each perforation zone. A production rate of each productive layer is determined taking into account thicknesses of the perforation zones and using results of temperature measurements acquired in a period between an end of an initial production stage characterized by strong impact of a volume of the wellbore and quick flow temperature changes in the wellbore, and a time when the bottom-hole zone cooling effect on the temperature measurements becomes insignificant.

Abstract: A method for determining the profile of fluids inflowing into multi-zone reservoirs provides for a temperature measurement in a wellbore during the return of the wellbore to thermal equilibrium after drilling and determining a temperature of the fluids inflowing into the wellbore from each pay zone after perforation at an initial stage of production. Specific flow rate for each pay zone is determined by a rate of change of the measured temperatures.

Abstract: Method comprises measuring temperature along an injection well, measuring a steam quality and an injection rate at an inlet of the injection well and estimating a pressure distribution profile. Then a steam injection profile is estimated using the obtained pressure distribution profile and the measured injection rate combined with a one-dimensional injection well model for pressure losses in the well and heat exchange between an injection well tubing and an annulus. The obtained steam injection profile is used as an input parameter for a set of two-dimensional cross-sectional analytical SAGD models. The models are based on energy conservation law and take into account reservoir and overburden formation properties, heat losses into the reservoir and overburden formation impact on production parameters and SAGD characteristics. SAGD process characteristics are estimated from the set of two-dimensional cross-sectional analytical SAGD models.

Abstract: Method is directed to determining a fluid influx profile and near-wellbore area parameters in multi-layered reservoirs. A bottomhole pressure in a wellbore is measured. After operation of the wellbore at a constant production rate, the production rate is changed. A bottomhole pressure is measured together with a fluid influx temperature for each productive layer. Graphs of the fluid influx temperature measured as a function of time and of a derivative of this temperature with respect to a logarithm of a time passed after the production rate is changed as a function of time are plotted. Relative production rates and skin factors of the productive layers are calculated based on these graphs.

Abstract: The apparatus for a borehole influx fluid parameters measurement comprises an enclosure open on two adjacent sides and having a poorly deformable heat-insulating rear wall, a cover and side walls made of elastically deformable heat-insulating material. Inside the enclosure a cellular structure of elastically deformable heat-insulating material is mounted with the gap relative to the enclosure's rear wall and having the through cells insulated from one another. Said cells forming the apparatus inlet openings on one side of the cellular structure and on the other side they are connected with the gap, the total area of the inlet openings significantly exceeds the area of the structure side surface they are located at. The transducers for the measurement of the influx fluid parameters are disposed inside the cells.

Abstract: A thermal disturbance of a rock mass is performed by circulating a fluid through a borehole, a temperature of the circulation fluid differs from a temperature of the rock mass. Before, during and after the thermal disturbance, differential electrical signals proportional to a temperature difference between two points along the borehole are registered by at least one pair of differential temperature transducers disposed along an axis of the borehole Differential electrical signals measured before the thermal disturbance are compared with differential electrical signals measured during the thermal disturbance and differential electrical signals of different temperature transducers positioned along the wellbore borehole are compared with one another. Based on the comparison results of different rock mass areas with different properties are identified.

Abstract: Method for determination of a fluid influx profile and near-wellbore area parameters comprises measuring a first bottomhole pressure and after operating a well at a constant production rate changing the production rate and measuring a second bottomhole pressure. A wellbore fluid temperature over an upper boundary of a lowest productive layer and wellbore fluid temperatures above and below other productive layers are measured and relative production rates and skin factors of the productive layers are calculated from measured wellbore fluid temperatures and measured first and second bottomhole pressures.

Abstract: Method for preheating an oil reservoir comprises injecting saturated or superheated steam at an initial injection pressure into a tubing placed inside a well drilled in the oil reservoir. Steam temperature at an outlet of the tubing is measured and a heat flow from the well to the oil reservoir is calculated. An optimal steam injection rate when steam quality of the injected steam at the tubing outlet becomes greater than zero, is calculated, the optimal steam injection rate ensuring compensation of the heat flow from the well to the oil reservoir with the heat of steam condensation. A steam injection rate is decreased to the calculated optimal steam injection rate value by decreasing the initial injection pressure providing constant temperature at the outlet of the tubing.

Abstract: A method for the determination of an inflow profile and bottom-hole area parameters (perforation zone parameters, bottom-hole area pollution parameters) in a multipay well comprises changing a production rate and measuring a temperature of a fluid flowing into the well as a function of time for each pay zone. Then a derivative of this temperature with respect to a logarithm of a time passed after the well production rate has been changed for each pay zone is determined. An inflow profile and other parameters are calculated based on a value of said derivative when it becomes constant and on a time after which the value of the derivative becomes constant.

Abstract: Method for determination of a fluid influx profile and near-wellbore area parameters comprises measuring a first bottomhole pressure and after operating a well at a constant production rate changing the production rate and measuring a second bottomhole pressure. A wellbore fluid temperature over an upper boundary of a lowest productive layer and wellbore fluid temperatures above and below other productive layers are measured and relative production rates and skin factors of the productive layers are calculated from measured wellbore fluid temperatures and measured first and second bottomhole pressures.

Abstract: Method for determination of a fluid influx profile and near-wellbore area parameters comprises measuring a first bottomhole pressure and operating a well at a constant production rate. After changing the production rate a second bottomhole pressure is measured together with a fluid influx temperature for each productive layer. Relative production rates and skin factors of the productive layers are calculated from measured fluid influx temperatures and measured first and second bottomhole pressures.

Abstract: The rock mass thermal excitation is performed by means of pumping the flush fluid through the wellbore using a tubing string, the flush fluid temperature differs from the rock mass temperature. Before the thermal excitation, during the thermal excitation and after the termination thereof differential electrical signals proportional to the well bore temperature difference are registered by at least one pair of the temperature transducers positioned along the wellbore axis. The distances between the transducers in the pairs and the number of pairs is selected in advance based on the required accuracy of the determination of the rock mass areas with different properties, minimum and maximum possible length of the rock mass areas identified and the nature and degree of the wellbore temperature noise.

Abstract: The apparatus for a borehole influx fluid parameters measurement comprises an enclosure open on two adjacent sides and having a poorly deformable heat-insulating rear wall, a cover and side walls made of elastically deformable heat-insulating material. Inside the enclosure a cellular structure of elastically deformable heat-insulating material is mounted with the gap relative to the enclosure's rear wall and having the through cells insulated from one another. Said cells forming the apparatus inlet openings on one side of the cellular structure and on the other side they are connected with the gap, the total area of the inlet openings significantly exceeds the area of the structure side surface they are located at. The transducers for the measurement of the influx fluid parameters are disposed inside the cells.