Abstract: A wellbore is plugged using a bismuth alloy. In one embodiment, the bismuth alloy comprises an alloy of bismuth and tin. In another embodiment, the bismuth alloy comprises an alloy of bismuth and silver. The wellbore can be arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance. Other aspects are described and claimed.

Abstract: Methods and systems are provided for controlling gas lift in at least one production well, which determine a quadratic function that relates flow rate or value of oil produced from a production well to gas flow rate for gas injected into the production well based on flow rate measurements for gas injected into the production well and corresponding flow rate measurements of oil produced from the production well. The quadratic function is used to determine an optimal flow rate for gas injected into the production well. The optimal flow rate for gas injected into the production well is used to control the flow rate of gas injected into the production well, and an oil flow rate produced from the production well is measured at the optimal gas flow rate for iterative processing to refine the quadratic function and determination of optimal gas flow rate if need be.

Abstract: Systems and methods presented herein generally relate to a tool for determining a refractive index of a formation fluid using attenuated total reflection. The tool includes a body having a fluid admitting assembly and a flow line that receives the formation fluid. The tool also includes two different crystals having faces in contact with fluid in the flow line. The tool further includes at least one light source coupled to the crystals and configured to direct light into the crystals. In addition, the wavelength, the refractive indices, and the angles of incidence are configured such that the light undergoes total internal reflection at interfaces between the crystals and the formation fluid. The tool also includes at least one light detector coupled to the crystals and configured to measure reflected light exiting the crystals. The tool further includes at least one processor coupled to the at least one light detector.

Abstract: A method can include receiving pressure data with respect to time acquired via a pressure sensor disposed in an uphole region of a bore of a well, where a plug is disposed in the bore to define the uphole region to one side of the plug and a corresponding downhole region to the other side of the plug; using physical properties of liquid in the uphole region and thermal information, computing a temperature induced density variation of the liquid in the uphole region; and, based at least in part on at least a portion of the pressure data and the temperature induced density variation of the liquid, determining a state of the plug and the bore from a plurality of states.

Abstract: A method can include receiving pressure data with respect to time acquired via a pressure sensor disposed in an uphole region of a bore of a well, where a plug is disposed in the bore to define the uphole region to one side of the plug and a corresponding downhole region to the other side of the plug; using at least physical properties of liquid in the uphole region and thermal information, computing a temperature and gravitational head induced density variation of the liquid in the uphole region; and, based at least in part on at least a portion of the pressure data and the temperature and gravitational head induced density variation of the liquid, determining a state of the plug and the bore from a plurality of states.

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.

Abstract: A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

Abstract: A wellbore is plugged using a bismuth alloy. In one embodiment, the bismuth alloy comprises an alloy of bismuth and tin. In another embodiment, the bismuth alloy comprises an alloy of bismuth and silver. The wellbore can be arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance. Other aspects are described and claimed.

Abstract: A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

Abstract: A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

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.

Abstract: Methods are provided for adaptive optimization of enhanced oil recovery project performance under uncertainty. Predictive physics-based reservoir simulation is used to estimate performance of the project. Input parameters of the model are divided into control variables and uncertain variables. The reservoir model is optimized to obtain values of control variables maximizing mean value of a chosen performance metric under initial uncertainty of formation and fluid properties. An efficient frontier can characterize dependence between the optimized mean value of the performance metric and its uncertainty expressed by the standard deviation. Global sensitivity analysis (GSA) is then applied to quantify and rank contributions from uncertain input parameters to the standard deviation of the optimized values of the performance metric. Additional measurements can be performed to reduce uncertainty in the high-ranking parameters.

Abstract: A method includes operating a downhole acquisition tool in a wellbore in a geological formation and performing formation testing using the downhole acquisition tool in the wellbore to determine at least one measurement associated within the geological formation, the wellbore, or both. The downhole acquisition tool includes one or more sensors that may detect the at least one measurement and the at least one measurement includes formation pressure, wellbore pressure, or both. The method also includes using a processor of the downhole acquisition tool to obtain a response characteristic associated with the formation, the wellbore, or both based on oscillations in the at least one measurement and determining at least one petrophysical property of the geological formation, the wellbore, or both, based on the response characteristic. The petrophysical property includes permeability, mud filter cake permeability, or both.

Abstract: A method includes operating a downhole acquisition tool in a wellbore in a geological formation and performing formation testing to determine at least one measurement associated within the formation, the wellbore, or both. The tool may include sensors to detect measurements including, for example, formation pressure and/or wellbore pressure. The tool may also include a processor to obtain at least one spectral characteristic associated with the measurement, which may include frequencies of oscillation. The processor may also determine one or more parameters, associated with an oscillation suppression process, based on the spectral characteristic and remove oscillations, including noise associated with fluctuations of a fluid level in the wellbore, in the measurement based on the parameters. Petrophysical parameters may be estimated based on the modified measurement.

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: Methods and systems are provided for controlling gas lift in at least one production well, which determine a quadratic function that relates flow rate or value of oil produced from a production well to gas flow rate for gas injected into the production well based on flow rate measurements for gas injected into the production well and corresponding flow rate measurements of oil produced from the production well. The quadratic function is used to determine an optimal flow rate for gas injected into the production well. The optimal flow rate for gas injected into the production well is used to control the flow rate of gas injected into the production well, and an oil flow rate produced from the production well is measured at the optimal gas flow rate for iterative processing to refine the quadratic function and determination of optimal gas flow rate if need be.

Abstract: A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

Abstract: A wellbore is plugged using a bismuth alloy. In one embodiment, the bismuth alloy comprises an alloy of bismuth and tin. In another embodiment, the bismuth alloy comprises an alloy of bismuth and silver. The wellbore can be arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance. Other aspects are described and claimed.

Abstract: A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

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.