Abstract: Methods are described for wettability characterization based on NMR measurements, which are sensitive to the surface wetting conditions of oil and water at the pore scale. The described methods make use of surface relaxation effects on the NMR relaxation (T2). Workflows are described to obtain wettability profiles of a porous media such as a rock either in the native state or prepared to a certain state in the laboratory. An underlying forward model is also described for the mixed wet and fractionally saturated pore spectrum. Outputs of the described inversion include continuous saturation and wettability profiles as a function of the pore sizes in the porous media, as well as an averaged value for saturation and wettability over the entire pore spectrum.

Abstract: A method for monitoring production from a methane hydrate reservoir includes obtaining a plurality of temperature measurements in a wellbore connected with the methane hydrate reservoir; and deriving a parameter relating to conversion of methane hydrate to carbon dioxide (CO2) hydrate by injection of liquid CO2, wherein the deriving uses a modeling program and the plurality of temperature measurements, wherein the modeling program uses at least one parameter relating to a thermodynamic properties that are substantially different between methane and CO2. The at least one parameter relating to thermodynamic properties may include Joule-Thomson coefficients of methane and CO2. The parameter relating to the conversion of methane hydrate to CO2 hydrate may include a ratio of methane and CO2 in a mixed fluid.

Abstract: Methods for managing an intelligent field, are provided. An exemplary method can include, for example, the steps of receiving well instrument data, processing the data, detecting a missing or faulty data period, applying a rule set and logics, estimating values for the missing or faulty data, validating the estimated values, and inserting the data in the data period.

Abstract: A method and system of characterizing a flow property of a production well site in a reservoir are provided. The method includes identifying a plurality of injection and production well sites in the reservoir; injecting fluid into selected injection well sites in accordance with an injection schedule; monitoring an output at the production well sites; determining a time delay between the selected injection sites and the production sites based on the monitored output using an estimated capacitance model; and characterizing a flow property of a production well site using the time delay and the estimated capacitance model.

Abstract: An apparatus and method for measuring the conductivity of borehole fluid. Based on the fluid conductivity, the fluid type may also be identified. The apparatus and method can be useful in differentiating between native water and injected water in oil recovery operations. The apparatus and method presented can also be used to calibrate testing and production equipment allowing for more reliable and accurate measurements. The apparatus and method presented can further be used to better characterize water to oil ratio in reservoirs.

Abstract: A method and system of locating discontinuities in a reservoir are provided. The method includes identifying a plurality of injection and production sites in the reservoir, injecting fluid into selected injection sites in accordance with an injection schedule, monitoring an output at the production sites, determining a time delay between the injection sites and the production sites based on the monitored output, and determining a location of discontinuities based on the determined time delay.

Abstract: A system, method, and computer readable medium for calculating well flow rates produced with electrical submersible pumps using measured voltage, current, frequency and pressure data. An efficiency to flow rate ratio is calculated from the voltage, current, and pressure data. The efficiency to flow rate ratio is used to obtain a non-dimensional flow rate. The flow rate through the electrical submersible pump is calculated from the non-dimensional flow rate.

Abstract: A method comprising: estimating a change in a characteristic of a subterranean formation into which a fluid has been injected via a well extending into the subterranean formation; building a multi-dimensional model balancing mass of the injected fluid, wherein the model is based on the estimated characteristic change; utilizing the model to determine the sensitivity of a borehole gravity tool in the well; measuring gravity with the borehole gravity tool at a plurality of stations along the well; and utilizing the model and the gravity measurements to locate the injected fluid in the subterranean formation.

Abstract: A method of providing a flow control device is disclosed, which one aspect may include: defining a flow rate; defining a desired relationship between a parameter of the flow control device that exhibits a substantial change when a selected property of the fluid changes in a first range and remains substantially constant when the selected property is in the second range; determining using a computer and a simulation program the relationship between the performance parameter and the selected property over the first range and the second range for the defined flow rate for a geometry of a flow through area of a flow control device; comparing the determined relationship of the performance parameter with the desired relationship; altering the geometry to a new geometry when the difference between the desired performance and the determined performance is outside a desired range; determining using the computer and the simulation program the relationship between the performance parameter and the selected property over

Abstract: The present disclosure provides a flowmeter including a vibrating element configured to be inserted in a measured fluid; a driver circuit to vibrate the vibrating element in its natural frequency of oscillation; one or more additional technology flow meters configured to measure an additional property of the fluid; a data acquisition circuit configured to measure signals effected by the flow of a multi-phase fluid; and a computer suitable to solve non-linear simultaneous equations. The fluid may include gas, oil and/or water. The fluid may also include solids.

Abstract: Methods and apparatus are described to use real-time measurement systems to detect the onset of compression induced microfracturing of fiber-reinforced composite materials. Measurements are described to detect the onset of compression induced microfracturing of fiber-reinforced composite materials to prevent catastrophic failures of aircraft components containing such materials. Methods and apparatus are described to prevent fluids and gases from invading any compression induced microfractures by coating surfaces of fiber-reinforced materials to reduce the probability of failure of such fiber-reinforced materials.

Abstract: A method of determining a permeability profile of a heavy-oil bearing formation includes pre-heating of the formation by circulation of steam in a well, creating an excessive pressure inside the well during the pre-heating stage, stopping circulation of steam in the well, measuring temperature along a well bore of the well using distributed temperature sensors, wherein the measuring is performed from a moment at which steam circulation stops until a thermally stable condition is achieved, creating a conductive heat exchange model relating a quantity of steam penetrated into the formation to a local permeability of the formation, the model being created using the temperature measurement results of the pre-heating stage for solving an inverse problem, and determining the formation permeability profile from the created model.

Abstract: A system and method estimate a property of an earth formation comprising hydrocarbon and non-hydrocarbon components. The method includes conveying a carrier down a borehole penetrating the earth formation, and performing a nuclear magnetic resonance (NMR) measurement on fluid in the earth formation with an NMR instrument disposed at the carrier to provide total NMR measurement data. The method also includes separating the total NMR measurement data into hydrocarbon-resultant NMR measurement data and non-hydrocarbon-resultant NMR measurement data, scaling a portion of the non-hydrocarbon-resultant NMR measurement data based on a correction factor to obtain scaled non-hydrocarbon-resultant NMR measurement data, and estimating the property based on the hydrocarbon-resultant NMR measurement data and the scaled non-hydrocarbon-resultant NMR measurement data.

Abstract: Methods, systems, and computer readable media are provided for fast updating of oil and gas field production optimization using physical and proxy simulators. A base model of a reservoir, well, or a pipeline network is established in one or more physical simulators. A decision management system is used to define uncertain parameters for matching with observed data. A proxy model is used to fit the uncertain parameters to outputs of the physical simulators, determine sensitivities of the uncertain parameters, and compute correlations between the uncertain parameters and output data from the physical simulators. Parameters for which the sensitivities are below a threshold are eliminated. The decision management system validates parameters which are output from the proxy model in the simulators. The validated parameters are used to make production decisions.

Abstract: A method and system for monitoring the integrity of a water aquifer is provided. The method and system generally monitors an aquifer for subsurface fractures, fluid intrusion, or water contamination. In one embodiment, the method and system may be utilized before, during, and after contaminating operations to monitor a water aquifer and generate reports detailing the effect of the contaminating operations on the water aquifer. The reports, and associated raw data, may be used as legal documents. For example, in one embodiment, an independent company is responsible for monitoring the aquifer and generating reports, which are then submitted to all interested parties, including the state for regulatory purposes.

Abstract: An improved method and computer system is provided, for analyzing the two- or three-dimensional movement of a fluid in an absorbent article that comprises fluid-swellable composite material, which comprises a fluid-swellable solid material, and that comprises void spaces in the fluid-swellable composite material, the fluid-swellable composite material being defined by a virtual two-dimensional or three-dimensional mesh, to determine the performance or property of at least one feature of the fluid-swellable composite material thereof, or the absorbent article, the method comprising: inputting one or more properties for the fluid-swellable (composite) material into a model and evaluating this to determine the performance of a feature of the absorbent article or fluid-swellable composite material thereof, the virtual model.

Abstract: An apparatus and method for estimating reservoir connectivity using gravity estimates at a fluid contact for each of two or more boreholes. The method may include identifying fluid contacts in the boreholes. The method may include additional gravity estimates at and/or between a well head and the fluid contact of each borehole. The method may include gravity estimates along a surface between well heads of the boreholes. The method may include estimating true vertical depth for the boreholes. The apparatus may include at least one gravimeter and a processor configured to estimate reservoir connectivity using estimates from the gravimeter.

Abstract: A method of modeling the spatial variation in wind resource at a prospective wind farm site. The method involves calculating terrain exposure at multiple locations of interest, such as the locations of meteorological towers and prospective wind turbine locations. Measured average wind speeds from the meteorological tower locations are empirically correlated with terrain exposure to create a model wherein annual average wind speed can be calculated for any location on the site as a function of terrain exposure. The method can use upwind terrain exposure, downwind terrain exposure, or both. It can also be used together with terrain elevation to create a robust three parameter model. The method requires wind measurements from at least two meteorological towers, with improved performance when measurements are available from a larger number of meteorological towers.

Abstract: Downhole gravity measurements are used to monitor the volumetric sweep of CO2 and estimate the fingering phenomenon if any. The gravity measurements have been found to be effective due to the high density contrast between CO2 and brine or oil which provides better and higher sensitivity. An analytical forward model is used to determine the location and shape characteristics of the flooding front. A strategy to monitor the movement of the CO2 flooding front and to predict the fingering phenomenon is used to provide a warning tool to improve the sweep efficiency, according to some embodiments.

Abstract: Methods for managing an intelligent field, are provided. An exemplary method can include receiving real-time dynamic field data, analyzing validity of the dynamic field data, validating values of the field data, validating a state/condition of a well, and flagging well components, well conditions, and/or well state validation issues.

Abstract: Apparatus and computer readable media for managing an intelligent field, are provided. An exemplary apparatus can include hydrocarbon well instruments, a SCADA system, a process integration server and/or dynamic field data analyzing computer, and memory/computer readable media storing a dynamic field data analyzing computer program. The computer program can include instructions that when executed cause the dynamic field data analyzing computer to perform various operations to include receiving real-time dynamic field data, analyzing validity of the dynamic field data, validating values of the field data, validating a state/condition of a well, and flagging well components, well conditions, and/or well state validation issues.

Abstract: A method of determining rate and phase of fluid produced from or injected into a hydrocarbon well includes obtaining first temperature and pressure measurements from sensors at the well. The first temperature and pressure measurements are applied to a plurality of predictive well models to calculate an estimated value of fluid rate and phase composition from each of the predictive well models responsive to the temperature and pressure measurements. A first fluid rate and phase composition result is derived from the estimate value of fluid rate and phase composition from each of the predictive well models.

Abstract: A method is described for monitoring a fluid flow in a flow line from a location in a subterranean reservoir to a surface storage or production facility using the steps of employing sensors located in the wellbore, along the flow line and surface systems for monitoring flow conditions, establishing parameters which determine the hydrocarbon phases like liquids and gases, precipitation of solid components from the fluid flow as a result of changes in temperature, pressure and compositions, setting alert parameters relating to the precipitation parameters, and determining an operating profile representative of present conditions along the flow line, wherein the precipitation parameters, the alert parameters and the operating profile and extrapolation of the operating profile are represented in a single parameter space.

Abstract: A method for determining permeability of a reservoir using a packer-probe formation testing tool. The elements of the method include generating, using a dual packer tool module, fluid flows from the reservoir into a wellbore, obtaining pressure data associated with the fluid flows using an observation probe tool module, wherein the packer-probe formation testing tool comprises the dual packer module and the observation probe tool module, identifying a portion of the pressure data corresponding to a spherical flow regime, determining horizontal permeability based on the portion of the pressure data, and displaying an output generated using the horizontal permeability.

Abstract: The instant disclosure is directed to a method of detecting an emulsion in a turbid brine, the method comprising the steps of disposing an aliquot of the turbid brine into a sample container to produce a test sample; adding one or more drops of a dye solution comprising an oil-soluble dye dissolved in a nonaqueous base fluid to said test sample; and determining the configuration of the dye solution after a period of time on a surface of the test sample, wherein a configuration of the dye solution forming a ring around the perimeter of the sample container at the interface of a wall of the sample container and the turbid brine indicates an emulsion is present in the turbid brine, and wherein a configuration of the dye solution forming a single dot or a plurality of dots on the surface of the turbid brine indicates an emulsion is not present in the turbid brine.

Abstract: A method for geosteering during directional drilling of a wellbore including a processor, a data storage, and client devices in communication with the processor through a network. The processor can receive data from directional drilling equipment and can present that data to users in an executive dashboard. Users can send data and/or commands to the directional drilling equipment. The executive dashboard can present a portion of interest in a stratigraphic cross section for user identification of the drill bit in the stratigraphic cross section, formations in the stratigraphic cross section, and other formation data. The method can be used to identify a projected path for the drill bit, import data, compute wellbore profiles and stratigraphic cross sections, plot actual drilling paths, overlay the actual drilling path onto the projected path, and present control buttons to the user.

Abstract: A system for geosteering during directional drilling of a wellbore including a processor, a data storage, and client devices in communication with the processor through a network. The processor can receive data from directional drilling equipment and can present that data to users in an executive dashboard. Users can send data and/or commands to the directional drilling equipment. The executive dashboard can present: a portion of interest in a stratigraphic cross section for user identification of: the drill bit in the stratigraphic cross section, formations in the stratigraphic cross section, and other formation data. The system can be used to: identify a projected path for the drill bit, import data, compute wellbore profiles and stratigraphic cross sections, plot actual drilling paths, overlay the actual drilling path onto the projected path, and present control buttons to the user.

Abstract: Disclosed are an apparatus and a method of measuring porosity and permeability of a carbon dioxide underground storage medium. Both of the porosity and the permeability are measured in the state that the confining pressure is applied once. The variation characteristic in the porosity and the permeability of the core sample according to the salt precipitation occurring when supercritical carbon dioxide is injected is continuously measured. The apparatus includes a holder receiving a core sample, a pressure pump applying a confining pressure to the core sample, a gas chamber storing gas and supplying supply the stored gas to the core sample, first to third pressure gauges measuring an internal pressure of the gas chamber and front and rear portions of the holder, and a gas flow meter measuring a flow rate of gas.

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 system for monitoring and display of representative parameters in a selected monitoring geography incorporates multiple sensor suites (10) deployed at selected measurement sites within a monitoring geography which provide output data. A computer (18) receives output from the sensor suites and incorporates a computational module (208) for processing of the sensor suite output data with respect to a selected model and integration and networking software (23) for selection of parameters in the computational module and display of selected visualizations of the processed data, Monitoring terminals (20) are deployed through a network (21) and connected to the computer under control of the integration and networking software. The terminals communicate with the computational module and receive and display results from the computational module.

Abstract: Apparatus, computer readable media, method and program code for determining well characterstics and pore architecture for a hydrocarbon well utilizing data available from conventional/standard electronic well logs, are provided. An example apparatus is configured to perform operations which include determining the value of well constants from well log data to include calculating water saturation, free water level location, wettability, and pore throat heterogeneity, and calculating/pore architecture at log resolution responsive thereto. This can be accomplished, for example, by accessing well log data from a conventional well log, determining a linear regression line responsive to parameters calculated from the well log data, the linear regression line having a slope and an intercept, and determining a value of each of a plurality of well constants responsive to a value of the slope and of the intercept of the linear regression line.

Abstract: A multi-phase process fluid is passed through a vibratable flowtube. Motion is induced in the vibratable flowtube. A first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube is determined, and an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property is determined. A corrected intermediate value is determined based on a mapping between the intermediate value and the corrected intermediate value. A phase-specific property of a phase of the multi-phase process fluid is determined based on the corrected intermediate value.

Abstract: Apparatus for in-situ wellbore measurements, said apparatus comprising one or more sensors arranged outside a wellbore, one or more actuators associated with the sensors, an electromagnetic transceiver situated inside a non-magnetic portion of wellbore conduit and mounted on an electric-line logging cable, a downhole interface unit also located on the electric-line cable for controlling communication to the apparatus. Also a method of in-situ wellbore measurements using said apparatus.

Abstract: Job monitoring methods and apparatus for logging-while-drilling equipment are disclosed. A disclosed example method includes obtaining a fluid associated with an underground geological formation, analyzing the fluid with one or more sensors to form respective ones of sensor outputs, identifying a downhole scenario associated with the fluid based on the sensor outputs, the identifying being performed while the sensors are within the underground geological formation, and selecting a telemetry frame type based on the identified downhole scenario.

Abstract: Methods, computer readable medium, apparatus, and program code for determining well characteristics and pore architecture for a hydrocarbon well utilizing data available from conventional/standard electronic well logs, are provided. An example of a method can include determining the value of well constants from well log data to include calculating water saturation, free water level location, wettability, and pore throat heterogeneity, and calculating pore architecture at log resolution responsive thereto. This can be accomplished, for example, by accessing well log data from a conventional well log, determining a linear regression line responsive to parameters calculated from the well log data, the linear regression line having a slope and an intercept, and determining a value of each of a plurality of well constants responsive to a value of the slope and of the intercept of the linear regression line.

Abstract: Clustering analysis is used to partition data into similarity groups based on mathematical relationships between the measured variables. These relationships (or prototypes) are derived from the specific correlation required between the measured variables (data) and an environmental property of interest. The data points are partitioned into the prototype-driven groups (i.e., clusters) based on error minimization. Once the data is grouped, quantitative predictions and sensitivity analysis of the property of interest can be derived based on the computed prototypes. Additionally, the process inherently minimizes prediction errors due to the rigorous error minimization during data clustering while avoiding overfitting via algorithm parameterization. The application used to demonstrate the power of the method is pressure gradient analysis.

Abstract: A method for evaluating inflow or outflow in a subterranean wellbore includes acquiring first and second axially spaced pressure measurements in the wellbore. The pressure measurements may then be processed to obtain an interval density of drilling fluid between the measurement locations. A tool string including a large number of axially spaced pressure sensors (e.g., four or more or even six or more) electronically coupled with a surface processor via wired drill pipe may be used to obtain a plurality of interval densities corresponding to various wellbore intervals. The interval density may be measured during static conditions or while drilling and may be further processed to compute a density of an inflow constituent in the annulus. Changes in the computed interval density with time may be used as an indicator of either an inflow event or an outflow event.

Abstract: Physical models of wells are used to determine rate and phase composition for fluid produced from or injected into the wells on a near real time and continuous basis. The method can be used to alert operators or others of conditions in a well or field to permit more immediate response. The method can be more tolerant of sensor faults, sensor drift, anomalous data or other occurrences which could otherwise lead to incorrect output. More than one model can be used to permit a hierarchy of calculation such that the rate and phase determination is more tolerant of anomalous data. The calculated rate and phase values from one or more wells can be reconciled against facility data.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: A method for characterizing fluid pumping effects on a subsurface formation includes (a) during pumping of fluid into the subsurface formation, detecting passive seismic signals related to fractures created in the subsurface formation. (b) A place of origin of the passive seismic signals is determined. (c) A seismic energy source is actuated for a plurality of actuations and an output thereof is beam steered toward the place of origin. (d) At least one acoustic property is determined for the place of origin using signals detected as a result of the plurality of actuations. The detected signals are beam steered toward the place of origin and are stacked over the plurality of actuations. (a), (b), (c) and (d) are repeated until the pumping is completed.

Abstract: A system for monitoring fluids at a drilling location, the system including a viscometer (210) having a heating cup and a pump (211) in clued communication with the heating cup, wherein the pump is configured to provide a flow of fluid from a fluid line inlet to the heating cup. The system also including a cleaning fluid tank (214) including communication with the heating cup, wherein the pump is configured to provide a flow of cleaning fluid from the cleaning fluid tank to the heating cup, and a system controller (217) configured to provide instructions to the pump for controlling the flow of cleaning fluid from the cleaning fluid tanks to the heating cup.

Abstract: A monitoring tool is provided for monitoring wells for flow anomalies. The temperatures of flowing well fluid and ambient temperature are monitored and various methods applied to indicate if a well is normal flowing, at risk of flow stoppage or cessation of flow. Approaches are described for determining trending indicators from actual flow temperatures compared to a normal flow relationship for establishing the presence of flow anomalies. Temperature sensors, onsite processors and communications upload data for display of well status flags on a mapping module enabling pro-active detection and preventative action by operators.

Abstract: A method is disclosed for determining the connectivity architecture of a hydrocarbon reservoir in terms of locally optimal paths between selected source points, e.g. wells. In one embodiment of the invention, a fast-marching method (133) is used to compute the distance field (or the time of arrival field) from N selected source points in a heterogeneous media, i.e. in a non-uniform velocity field. This is done by propagating N labeled (132) fronts simultaneously from N objects. Then, a method (134) is disclosed for detecting Voronoi curves or Voronoi surfaces, where fronts of differing labels meet each other. Then, saddle points are found on the Voronoi curves or surfaces (135), and each saddle point is used to determine a locally optimal path (136) between a pair of equidistant (from the saddle point), closest (to the saddle point) source points.

Abstract: Reservoir characterization based on observations of displacements at the earth's surface. One method of characterizing a reservoir includes the steps of: detecting a response of the reservoir to a stimulus, the stimulus causing a pressure change in the reservoir; and determining a characteristic of the reservoir from the response to the stimulus. The response may be the pressure change which varies periodically over time, or a set of displacements of a surface of the earth. In another example, a method includes the steps of: detecting a set of displacements of the earth's surface corresponding to a pressure change in the reservoir; and determining a characteristic of the reservoir from the surface displacements. In yet another example, a method includes the steps of: detecting a set of displacements of the earth's surface corresponding to a change in volume of the reservoir; and determining a characteristic of the reservoir from the surface displacements.

Abstract: Methods, systems, and computer readable media are provided for real-time oil and gas field production optimization using a proxy simulator. A base model of a reservoir, well, pipeline network, or processing system is established in one or more physical simulators. A decision management system is used to define control parameters, such as valve settings, for matching with observed data. A proxy model is used to fit the control parameters to outputs of the physical simulators, determine sensitivities of the control parameters, and compute correlations between the control parameters and output data from the simulators. Control parameters for which the sensitivities are below a threshold are eliminated. The decision management system validates control parameters which are output from the proxy model in the simulators. The proxy model may be used for predicting future control settings for the control parameters.

Abstract: The invention concerns a process for detecting scale deposit in the liquid supply means of a water pump driven machine comprising at least a water tank, a pump and a heating means, where water is pumped from the water tank and fed to the heating means, and where the pump is energized by a controller by providing the pump with an energizing signal to provide an intended water flow rate F, wherein the actual water flow rate f is measured and the discrepancy ? between the actual water flow rate f and the intended water flow rate F is directly and/or indirectly compared to an operating instruction related to scale deposit.

Abstract: Methods and related systems are described for analyzing phase properties in a microfluidic device. A fluid is introduced under pressure into microchannel, and phase states of the fluid are optically detected at a number of locations along the microchannel. Gas and liquid phases of the fluid are distinguished based on a plurality of digital images of the fluid in the microchannel. Bi-level images can be generated based on the digital images, and the fraction of liquid or gas in the fluid can be estimated versus pressure based on the bi-level images. Properties such as bubble point values and/or a phase volume distribution ratio versus pressure for the fluid are can be estimated based on the detected phase states of the fluid.

Abstract: Example methods and apparatus to determine phase-change pressures are disclosed. A disclosed example method includes capturing a fluid in a chamber, pressurizing the fluid at a plurality of pressures, measuring a plurality of transmittances of a signal through the fluid at respective ones of the plurality of pressures, computing a first magnitude of a first subset of the plurality of transmittances, computing a second magnitude of a second subset of the plurality of transmittances, comparing the first and second magnitudes to determine a phase-change pressure for the fluid.

Abstract: An example method comprises collecting formation temperature data along a wellbore extending into a subterranean formation, determining test operating parameter values, performing a wellbore hydraulic simulation of the response of wellbore fluid conditions to the test operating parameter values and the formation temperature data, determining whether the response of wellbore fluid conditions is indicative of one of a well control and a well stability problem, and initiating a test based on the determination whether the response of wellbore fluid conditions is indicative of one of a well control and a well stability problem.

Abstract: A method for estimating fluid volumes moved in compartmented areas of the subsoil, the method including the steps of a) performing a series of gradiometric measurement campaigns at pre-established time intervals in a survey field, in which the relative variation ?Vi of the fluid volumes contained in a corresponding compartmented area of the subsoil is known; b) determining, for each measurement campaign after the first campaign, a parameter P1i based on the entire survey area; and c) determining a variability law that correlates the parameter P1i to the known relative variation ?Vi in fluid volumes in the compartmented area of the subsoil.