Abstract: Described herein is an apparatus and methods for characterizing a fluid composition including exposing electrolyte to one fluid mixture, collecting a signal from an electrode in contact with the electrolyte, and simultaneously exposing the electrolyte to a second fluid, collecting a signal from a second electrode in contact with the electrolyte exposed to the second fluid, and comparing the signal difference between the electrodes with the Nerst equation wherein the temperature of the electrolyte is above 488° C. Carbon dioxide, nitrogen, and/or oxygen may be present in the fluid and/or the second fluid.

Abstract: A method of investigating an earth formation. A tool having a pressure sensor is used in a borehole to collect formation fluid pressure data over time. A pressure derivative curve is generated from the formation fluid pressure data by conducting a piecewise linear regression of the data having optimal window length values L determined by calculating a derivative with respect to L of a pressure derivative value (DD), and selecting values of L where DD has a transition that departs from oscillatory behavior to gradual change. The pressure derivative is calculated with piecewise linear regression with the optimal window length values 2L. Different L values are generated for different groups of data points obtained over time. The pressure derivative is then used for flow regime determination.

Abstract: Methods and apparatus are provided for determining down-hole the composition of natural gas from a formation. Some methods include downhole measurements of the near-infrared spectra and the Joule-Thomson coefficient of the gas, and processing the results of the downhole measurements in order to obtain a determination of the amounts of a plurality of natural gas components such as CH4, C2H6, CO2, N2, and H2S.

Abstract: Methods are provided for tracking carbon dioxide (CO2) migration in a hydrocarbon-bearing reservoir located under a cap rock in a formation. In one embodiment, at least one seismic source and a plurality of receivers are located in spaced boreholes in the formation with the sources and receivers located near or at the reservoir so that direct paths from the sources to the receivers extend through the reservoir. CO2 is injected from the borehole containing the seismic sources into the reservoir, and the sources are activated multiple times over days and seismic signals are detected at the receivers. From the detected signals, time-lapse travel delay of direct arrivals of the signals are found and are used to track CO2 in the reservoir as a function of time. In another embodiment, the sources and receivers are located above the reservoir, and reflected waves are utilized to track the CO2.

Abstract: Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.

Abstract: Methods and systems are provided for recovery of oil from a subterranean reservoir employing nanofluid injection at a controlled flow rate. The method comprises the step of injecting nanofluid through at least one well that traverses the subterranean reservoir and into the subterranean reservoir at a controlled flow rate. And, the system comprises: at least one well that traverses the subterranean reservoir; and injection means for injecting nanofluid through the well and into the subterranean reservoir at a controlled flow rate.

Abstract: Consolidated porous media samples and methods for their manufacture are described herein. An assembly has an outer tube having a first softening temperature and a sintered glass construct formed from plurality of beads of multiple sizes. The sintered glass construct defines pores and at least one fracture or channel. The assembly is formed by suspending at least one sheet or wire of dissolvable material in the outer tube, packing beads of different sizes around the sheet or wire, sintering the beads with the sheet or wire located therein at a temperature below the softening temperature of the tube, and dissolving the sheet or wire to generate a sintered construct defining at least one fracture or channel.

Abstract: Methods are provided for determining saturation parameters of a formation while sampling the formation. Flow rate and pressure data may be used in order to provide mobility information close to the probe. In turn, the mobility information may be used in conjunction with at least water fraction information in order to provide an estimation of saturation parameters of the formation such as maximum residual oil saturation Sorm, connate water saturation Swc, and residual water saturation Swr. Resistivity measurements may be used to help in the estimation of the saturation parameters. Initial estimations may be used as the starting parameters for a full parameter inversion. An interpretation scheme in the absence of invasion details is provided.

Abstract: Methods are disclosed for assigning a value to a geological asset or information relating thereto in the presence of private and public sources of uncertainties. The private and public uncertainties associated with a geological asset or information associated therewith are defined, and private uncertainties are assigned a subjective probability representing the best state of knowledge currently available. A multi-dimensional valuation-time lattice is constructed using the subjective probabilities for the private uncertainties and using risk-neutral probabilities for the public uncertainties. A backward recursion through the multi-dimensional lattice is performed in order to generate a present value for the asset given the present information available. During the backward recursion, a tally of delta hedging coefficients is generated and stored in order to provide an operational “map” or “decision pathway” should the project move forward.

Abstract: Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.

Abstract: Methods are provided for measuring the permeability and/or porosity of a rock sample having an “ultra-low” permeability while accounting for adsorption. The rock sample may be a sample obtained from a geological formation. The methods account for adsoption of gas within the rock samples.

Abstract: Embodiments include constructing a reservoir model of an earth formation. The method may also include selecting a predetermined set of fundamental parameters to describe the earth formation and assigning initial values for the predetermined set of fundamental parameters for each of the plurality of layers. The method may include using the initial values for each of the plurality of layers. The method may include computing physical-response-relevant properties as a function of space and time for each of the plurality of layers using the solutions and then computing tool responses using the physical-response-relevant properties. The method may include installing an electrode array between an insulation portion of a metal casing provided in a borehole and a physical formation and obtaining formation measurement information from the electrode array, comparing the formation measurement information to the computed tool response to obtain an error signal and modifying the initial values in an iterative process.

Abstract: Apparatus and calibration methods are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. The apparatus uses a gas source, a sample chamber, chambers of calibrated volume, and pressure measurement devices.

Abstract: Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.

Abstract: Methods and apparatus are provided for determining down-hole the composition of natural gas from a formation. Some methods include downhole measurements of the near-infrared spectra and the Joule-Thomson coefficient of the gas, and processing the results of the downhole measurements in order to obtain a determination of the amounts of a plurality of natural gas components such as CH4, C2H6, CO2, N2, and H2S.

Abstract: Methods and apparatus are provided for determining the refractive index of a downhole fluid. Two unalike crystals are provided having faces in contact with fluid in the fluid flow line of a borehole tool. The crystals are chosen to have different refractive indices and/or different angles of incidence, but to provide total internal reflection for light that is directed through the crystals to the crystal/fluid interface. The measured attenuations for each crystal are used in conjunction with the known refractive indices and angles of incidence of said crystals to determine the refractive index of the fluid.

Abstract: A rechargeable power system comprising: a drill string configured to operate in a well bore, the drill string comprising: a fuel cell system; a generator in electrical communication with the fuel cell system; a turbine, configured to rotate due to an impingement of drilling mud on one or more turbine blades, the turbine in operable communication with the generator; and where the fuel cell system is configured to provide power at least when drilling mud is not circulating in the well bore, and further configured to be recharged by the generator when drilling mud is circulating in the well bore. A method for operating a rechargeable downhole fuel cell. The method comprises: monitoring a fluid supply pressure; determining whether the fluid supply pressure is below a threshold value; and stopping a fuel cell discharge if the fluid supply pressure is below the threshold value.

Abstract: A method of investigating an earth formation. A tool having a pressure sensor is used in a borehole to collect formation fluid pressure data over time. A pressure derivative curve is generated from the formation fluid pressure data by conducting a piecewise linear regression of the data having optimal window length values L determined by calculating a derivative with respect to L of a pressure derivative value (DD), and selecting values of L where DD has a transition that departs from oscillatory behavior to gradual change. The pressure derivative is calculated with piecewise linear regression with the optimal window length values 2L. Different L values are generated for different groups of data points obtained over time. The pressure derivative is then used for flow regime determination.

Abstract: Methods and systems are provided for recovery of oil from a subterranean reservoir employing nanofluid injection at a controlled flow rate. The method comprises the step of injecting nanofluid through at least one well that traverses the subterranean reservoir and into the subterranean reservoir at a controlled flow rate. And, the system comprises: at least one well that traverses the subterranean reservoir; and injection means for injecting nanofluid through the well and into the subterranean reservoir at a controlled flow rate.

Abstract: Methods for interpreting pressure transient tests and predicting future production for a well are provided. In one embodiment, a method for predicting future production includes beginning a pressure transient test within a well at a wellsite and obtaining pressure measurements of well fluid during the pressure transient test. The method can also include using the obtained pressure measurements to determine probabilistic estimates of input parameters of a pressure transient reservoir model while continuing the pressure transient test. Future production from the well can then be estimated based on the probabilistic estimates of the input parameters. Other methods and systems are also disclosed.