Abstract: Methods and systems, including computer programs encoded on a computer storage medium can be used for generating dynamic reservoir descriptions using geostatistics in a geological model. Data processing techniques can be used by a computing system to automate processes for generating, and updating (e.g., in real-time), subsurface reservoir models. An integrated methodology and hardware systems are described for determining properties of a reservoir in a subterranean region using a geological model based on seismic data and transient pressure data. The methodology and automated approaches employ technologies relating to machine learning and artificial intelligence (AI) to process seismic data and information relating to seismic facies.

Abstract: Systems and methods include a computer-implemented method for using first- and second-order derivatives from discrete pressure data of a well to characterize the well and intersected reservoir under dynamic conditions. Discrete data for the well and associated reservoir is arranged chronologically. First- and second-order derivatives of pressure versus a time series are determined at a first focal point using a five-point function considering beginning and ending points in a time period. First- and second-order derivatives are determined at successive focal points, applying terminal corrections. Numerical values and plots of first- and second-order derivative profiles are presented. Diagnostic plots and data for determining geological features for the associated reservoir and well parameters are generated. Reservoir simulation models are executed to generate a forecast of future production rates under different constraints.

Abstract: Systems and methods include a method for generating a high-resolution advanced three-dimensional (3D) transient model that models multiple wells by integrating pressure transient data into a static geological model. A crude 3D model is generated from a full-field geological model that models production for multiple wells in an area. A functional 3D model is generated from the crude 3D model. An intermediate 3D model is generated by calibrating the functional 3D model with single-well data. An advanced 3D transient model is generated by calibrating multi-well data in the functional 3D model.

Abstract: Systems and methods include a computer-implemented method for characterizing low-permeability reservoirs by using numerical models. A numerical model modeling production of a well is prepared using reservoir data and well data. The numerical model is updated, including adjusting numerical model properties, until results of performing a quality assurance/quality control check indicate that the numerical model is within acceptable limits. Pressure derivatives are extracted from a transient test to create a functional numerical model. Simulations are run on the functional numerical model and reservoir features and properties are adjusted until acceptable results are achieved on: 1) a pressure match between pressures modeled in the functional numerical model and transient pressures of the well, and 2) a log-log plot derivative match between a pressure derivative of the functional numerical model and a pressure derivative of the transient pressures of the well.

Abstract: A method of estimating reservoir properties is disclosed. The method includes obtaining downhole pressure data during a drill stem test in a wellbore penetrating a reservoir, computing a first linearity measure of a first diagnostic plot, wherein the first diagnostic plot represents a first dependency of the downhole pressure data on a linear-scale with respect to inverse time on a linear-scale, determining, based at least on the first linearity measure, data sufficiency of the drill stem test, and generating, from the downhole pressure data and based at least on the data sufficiency, an estimation of the reservoir properties.

Abstract: Methods and systems, including computer programs encoded on a computer storage medium can be used for generating dynamic reservoir descriptions using geostatistics in a geological model. Data processing techniques can be used by a computing system to automate processes for generating, and updating (e.g., in real-time), subsurface reservoir models. An integrated methodology and hardware systems are described for determining properties of a reservoir in a subterranean region using a geological model based on seismic data and transient pressure data. The methodology and automated approaches employ technologies relating to machine learning and artificial intelligence (AI) to process seismic data and information relating to seismic facies.

Abstract: Systems and methods include a method for generating a high-resolution advanced three-dimensional (3D) transient model that models multiple wells by integrating pressure transient data into a static geological model. A crude 3D model is generated from a full-field geological model that models production for multiple wells in an area. A functional 3D model is generated from the crude 3D model. An intermediate 3D model is generated by calibrating the functional 3D model with single-well data. An advanced 3D transient model is generated by calibrating multi-well data in the functional 3D model.

Abstract: Systems and methods include a computer-implemented method for characterizing low-permeability reservoirs by using numerical models. A numerical model modeling production of a well is prepared using reservoir data and well data. The numerical model is updated, including adjusting numerical model properties, until results of performing a quality assurance/quality control check indicate that the numerical model is within acceptable limits. Pressure derivatives are extracted from a transient test to create a functional numerical model. Simulations are run on the functional numerical model and reservoir features and properties are adjusted until acceptable results are achieved on: 1) a pressure match between pressures modeled in the functional numerical model and transient pressures of the well, and 2) a log-log plot derivative match between a pressure derivative of the functional numerical model and a pressure derivative of the transient pressures of the well.

Abstract: A segregated flow mechanism of oil and water usually takes place in the presence of strong gravity forces in subsurface environments, having specific geometrical and petrophysical properties undergoing simultaneous flow of multiphase fluids. The segregated flow of oil and water is modeled as a two-layer reservoir system, based on the observed data. Accurate estimates or measures of the values of phase mobility of oil and water, in addition to the actual flow capacity of the formation are provided. Reliable reservoir characterizations and reserve estimations are provided based on the in-situ conditions of oil and water in the reservoir.

Abstract: A segregated flow mechanism of oil and water usually takes place in the presence of strong gravity forces in subsurface environments, having specific geometrical and petrophysical properties undergoing simultaneous flow of multiphase fluids. The segregated flow of oil and water is modeled as a two-layer reservoir system, based on the observed data. Accurate estimates or measures of the values of phase mobility of oil and water, in addition to the actual flow capacity of the formation are provided. Reliable reservoir characterizations and reserve estimations are provided based on the in-situ conditions of oil and water in the reservoir.

Abstract: A measure of inter-reservoir cross flow rate between adjacent reservoir layers which are productive of hydrocarbons is determined. With passage of time, pressure differentials between reservoir layers can grow due to continuous production from an active layer. In addition, the flow area between an active layer and adjacent layers can grow with time for a given reservoir system. These changing pressure and flow conditions with time can contribute to substantial amounts of cross flow rates, which need to be accounted for when characterizing the commercial producibility of the active layer. The inter-reservoir cross flow rate is based on a measure of specific permeability and of cross flow rate within a reservoir layer which is obtained from pressure transient tests of the reservoir formations.

Abstract: Provided in some embodiments are systems and methods for transient-pressure test of an oil reservoir water injection well system. Embodiments provide for determining a fracturing injection rate for the well, setting a test injection rate preferably below the fracturing injection rate, conducting a stabilized injection of water into a wellbore of the well at the test injection rate for a prescribed period, and conducting a fall-off test including shutting-in the well for a prescribed fall-off period, and acquiring test data indicative of fluid pressure in the wellbore of the well during the injection and the fall-off periods. Embodiments also provide for generating a model prediction, comparing the model to the test data to determine whether it is a match for the well, and associating the parameter values with the well, including the severity and the location of the shallow damage, if the reservoir model is a match.

Abstract: Provided are systems and methods for developing a hydrocarbon reservoir including determining properties of a well including a wellbore extending into a tested layer of a multi-layer hydrocarbon reservoir including a barrier located between the tested layer and an adjacent layer of the multi-layer hydrocarbon reservoir, determining a point in time at which a value of a rate of influx of production fluid across the barrier from the adjacent layer and into the tested layer corresponds to a production contribution tolerance value for the well, determining a derivative of a profile of pressure in the targeted layer as a function of radial distance from the wellbore of the well at the point in time, and determining a drainage radius for the well corresponding to the derivative of the profile of pressure in the targeted layer and a pressure derivative tolerance value.

Abstract: A segregated flow mechanism of oil and water usually takes place in the presence of strong gravity forces in subsurface environments, having specific geometrical and petrophysical properties undergoing simultaneous flow of multiphase fluids. The segregated flow of oil and water is modeled as a two-layer reservoir system, based on the observed data. Accurate estimates or measures of the values of phase mobility of oil and water, in addition to the actual flow capacity of the formation are provided. Reliable reservoir characterizations and reserve estimations are provided based on the in-situ conditions of oil and water in the reservoir.

Abstract: A segregated flow mechanism of oil and water usually takes place in the presence of strong gravity forces in subsurface environments, having specific geometrical and petrophysical properties undergoing simultaneous flow of multiphase fluids. The segregated flow of oil and water is modeled as a two-layer reservoir system, based on the observed data. Accurate estimates or measures of the values of phase mobility of oil and water, in addition to the actual flow capacity of the formation are provided. Reliable reservoir characterizations and reserve estimations are provided based on the in-situ conditions of oil and water in the reservoir.

Abstract: Crossflow between two adjacent reservoir layers through leaky cement sheaths in offset wells during transient-pressure tests in one of the two reservoir layers is diagnosed and quantified. The obtained measures are determined based on individual well and layer properties. The pressure drawdown in the reservoir layer in which pressure transient testing is being performed is measured as a function of time. The longitudinal conductivity of a leaky cement sheath in an offset well and the pressure drawdown in the tested reservoir layer simultaneously control the crossflow rate to the tested reservoir layer from the adjacent reservoir layer at a given time.

Abstract: Provided are systems and methods for developing a hydrocarbon reservoir including determining properties of a well including a wellbore extending into a tested layer of a multi-layer hydrocarbon reservoir including a barrier located between the tested layer and an adjacent layer of the multi-layer hydrocarbon reservoir, determining a point in time at which a value of a rate of influx of production fluid across the barrier from the adjacent layer and into the tested layer corresponds to a production contribution tolerance value for the well, determining a derivative of a profile of pressure in the targeted layer as a function of radial distance from the wellbore of the well at the point in time, and determining a drainage radius for the well corresponding to the derivative of the profile of pressure in the targeted layer and a pressure derivative tolerance value.

Abstract: A measure of the hydraulic conductivity, FC, is obtained to characterize the leaky medium behind well casing between adjacent hydrocarbon producing layers is a subsurface reservoir. The value of FC can be utilized in estimating the rate of flow from a secondary reservoir layer contributing to the total production through the wellbore based on the respective well pressures at a given time. The well pressures are calculated from a model based on the individual properties of and the amounts of fluid produced from these layers. Once there is a reasonable match between the calculated pressures and the measured pressures during a transient test, the parameters that have been used in calculating the model pressures are stored as characteristic parameters of the reservoir system. Such characteristic parameters are utilized in assessing the commercial producibility of the reservoirs.

Abstract: A segregated flow mechanism of oil and water usually takes place in the presence of strong gravity forces in subsurface environments, having specific geometrical and petrophysical properties undergoing simultaneous flow of multiphase fluids. The segregated flow of oil and water is modeled as a two-layer reservoir system, based on the observed data. Accurate estimates or measures of the values of phase mobility of oil and water, in addition to the actual flow capacity of the formation are provided. Reliable reservoir characterizations and reserve estimations are provided based on the in-situ conditions of oil and water in the reservoir.

Abstract: Provided in some embodiments are systems and methods for transient-pressure test of an oil reservoir water injection well system. Embodiments provide for determining a fracturing injection rate for the well, setting a test injection rate preferably below the fracturing injection rate, conducting a stabilized injection of water into a wellbore of the well at the test injection rate for a prescribed period, and conducting a fall-off test including shutting-in the well for a prescribed fall-off period, and acquiring test data indicative of fluid pressure in the wellbore of the well during the injection and the fall-off periods. Embodiments also provide for generating a model prediction, comparing the model to the test data to determine whether it is a match for the well, and associating the parameter values with the well, including the severity and the location of the shallow damage, if the reservoir model is a match.