A method for determining properties of hydraulic fractures from measurements of pressure in a well made after stopping pumping fracturing fluid into the well (shut in) includes determining a first time after shut in whereinafter a decrease in measured pressure is caused by fluid leak off in a fracture. A second time after shut in is determined whereinafter the decrease in pressure is caused by fluid leak off, fracture growth and fluid pressure equilibration in the fracture. A third time after shut in is determined whereinafter the decrease in pressure is caused by fluid leak off, fracture growth, fluid pressure equilibration in the fracture and pressure drop in a near wellbore zone. Values of fluid efficiency, minimum stress and net pressure which are determined result in a calculated pressure with respect to time matching the pressure measurements within a predetermined threshold.
A method for determining flowing fluid pressure loss in a well includes moving fluid through a well pipe and perforations in a well pipe at a first rate. A pressure of the fluid moving at the first rate is measured. The rate of moving fluid is changed to a second rate. The rate is changed so as to induce tube waves in the well. Pressure of the fluid moving at the second rate is measured. The measured pressures are used to determine frictional fluid pressure loss in the well pipe and frictional and fluid pressure loss through the perforations. The measured pressures and determined frictional fluid pressure losses are used to determine a fluid pressure outside the perforations.
G01N 11/04 - Investigating flow properties of materials, e.g. viscosity or plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
5.
Method of measuring reservoir and fracture strains, crosswell fracture proximity and crosswell interactions
A method for determining change in stress in a reservoir formation includes inducing a pressure pulse in a first well hydraulically connected by a fracture to the reservoir formation. A stress-related attribute of the fracture is determined from reflection events detected in pressure measurement made in the first well as a result of the inducing the pressure pulse. The inducing and determining are repeated to estimate changes in the stress-related attribute with respect to time. A method for determining and localizing type of interaction between a treated well and an observation well by monitoring pressure and fracture changes in the observation well.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
A method for determining properties of hydraulic fractures from measurements of pressure in a well made after stopping pumping fracturing fluid into the well (shut in) includes determining a first time after shut in whereinafter a decrease in measured pressure is caused by fluid leak off in a fracture. A second time after shut in is determined whereinafter the decrease in pressure is caused by fluid leak off, fracture growth and fluid pressure equilibration in the fracture. A third time after shut in is determined whereinafter the decrease in pressure is caused by fluid leak off, fracture growth, fluid pressure equilibration in the fracture and pressure drop in a near wellbore zone. Values of fluid efficiency, minimum stress and net pressure which are determined result in a calculated pressure with respect to time matching the pressure measurements within a predetermined threshold.
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a borehole drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the borehole for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the borehole and its real-time implementation.
E21B 47/095 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes by detecting acoustic anomalies, e.g. using mud-pressure pulses
8.
DETECTING OPERATIONAL ANOMALIES FOR CONTINUOUS HYDRAULIC FRACTURING MONITORING
A method for detecting operating anomalies during hydraulic fracturing includes inducing tube waves in a well during pumping a hydraulic fracture treatment. At least one of pressure and time derivative of pressure in the well is measured. The measured at least one of pressure and time derivative of pressure is transformed into the cepstrum domain. An operational anomaly is detected by determining a change in cepstral quefrency corresponding to a two-way travel time of the tube waves and resonances in the well.
A method for predicting fracture treatment performance includes inducing tube waves in a well drilled through a formation to be fracture treated. A polarity of reflected tube waves in the well is determined, and using the reflected tube waves, hydraulic conductivity of at least one zone in the well hydraulically connected to the formation is estimated. The estimated hydraulic conductivity is compared to a selected threshold. The selected threshold is based on pumping parameters and pumping pressure behavior of at least one pumped hydraulic fracture treatment. A warning signal is generated when the hydraulic conductivity is below the selected threshold and/or the determined polarity indicates a closed boundary condition so that the treatment may be adjusted to avoid screenouts and other operational and treatment issues.
A method for steering a well based on rock properties and obtaining natural fracture information includes inducing tube waves in the well during drilling the well. Acoustic energy is measured in the well. The energy comprises tube wave reflections from formations adjacent to the well. The measured acoustic energy is inverted to determine at least one of a rock property, a near wellbore hydraulic conductivity, and natural fracture occurrence. A trajectory of the well is adjusted to maintain the at least one of a rock property, near wellbore hydraulic conductivity and natural fracture occurrence. An n optimized, well-customized hydraulic fracturing design may be created based on the measured natural fracture properties. A method to optimize hydraulic fracturing treatment based on measured natural fracture properties during drilling.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B 43/267 - Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
A method for treating a well includes hydraulically isolating an interval in a first well having a plurality of intervals along the first well, each interval having been fracture treated. A tube wave is induced in the first well in the isolated interval. Reflections are detected from the induced tube wave. Hydraulic boundary condition and hydraulic conductivity of a fracture connected to the first well in the isolated interval are determined using the detected reflections. A refracture treatment is performed in the isolated interval when the hydraulic boundary condition and the hydraulic conductivity are within a predetermine range.
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 33/124 - Units with longitudinally-spaced plugs for isolating the intermediate space
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
A method for determining change in stress in a reservoir formation includes inducing a pressure pulse in a first well hydraulically connected by a fracture to the reservoir formation. A stress-related attribute of the fracture is determined from reflection events detected in pressure measurement made in the first well as a result of the inducing the pressure pulse. The inducing and determining are repeated to estimate changes in the stress-related attribute with respect to time.
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 47/095 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes by detecting acoustic anomalies, e.g. using mud-pressure pulses
E21B 43/267 - Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
E21B 47/09 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
G01V 1/40 - Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging
G01V 11/00 - Prospecting or detecting by methods combining techniques covered by two or more of main groups
13.
A METHOD OF MEASURING RESERVOIR AND FRACTURE STRAINS, CROSSWELL FRACTURE PROXIMITY AND CROSSWELL INTERACTIONS
A method for determining change in stress in a reservoir formation includes inducing a pressure pulse in a first well hydraulically connected by a fracture to the reservoir formation. A stress-related attribute of the fracture is determined from reflection events detected in pressure measurement made in the first well as a result of the inducing the pressure pulse. The inducing and determining are repeated to estimate changes in the stress-related attribute with respect to time.
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 43/267 - Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
E21B 47/09 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes
E21B 47/095 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes by detecting acoustic anomalies, e.g. using mud-pressure pulses
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
G01V 1/40 - Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging
G01V 11/00 - Prospecting or detecting by methods combining techniques covered by two or more of main groups
14.
Determining fracture properties using injection and step-rate analysis, dynamic injection test analysis, extracting pulse-type source signals from noisy data, and measuring friction parameters in a well
A method and a system to determine fracture properties during standard operations and injection tests. Fracture compliance, fracture closure pressure, and perforation friction can be determined using a combination of acoustic data, pressure decay data, and wellbore models. A method of automating and adjusting fracture design in real-time. A method and system to recover active, single active pulse data from a background noise dataset.
E21B 47/09 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 43/12 - Methods or apparatus for controlling the flow of the obtained fluid to or in wells
15.
HYDRAULIC FRACTURING, COMPLETION, AND DIVERTER OPTIMIZATION METHOD FOR KNOWN WELL ROCK PROPERTIES
A method for optimizing hydraulic fracturing includes characterizing a fracture induced by pumping fracturing fluid into a subsurface formation. The characterizing includes analyzing properties of reflected tube waves detected in a well. Change in expected characterization of the subsurface formation is modeled with respect to a modeled change in at least one parameter of the pumping fracturing fluid. The modeled change is compared to a measured change in the characterization with respect to an actual change in the at least one parameter. The modeled change and the measured change are used to train a machine learning algorithm to determine an optimized change in the at least one parameter.
A method for detecting operating anomalies during hydraulic fracturing includes inducing tube waves in a well during pumping a hydraulic fracture treatment. At least one of pressure and time derivative of pressure in the well is measured. The measured at least one of pressure and time derivative of pressure is transformed into the cep strum domain. An operational anomaly is detected by determining a change in cepstral quefrency corresponding to a two-way travel time of the tube waves and resonances in the well.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
17.
USING PRE-FRACTURING HYDRAULIC CONDUCTIVITY MEASUREMENTS TO AVOID FRACTURE TREATMENT PROBLEMS
A method for predicting fracture treatment performance includes inducing tube waves in a well drilled through a formation to be fracture treated. A polarity of reflected tube waves in the well is determined, and using the reflected tube waves, hydraulic conductivity of at least one zone in the well hydraulically connected to the formation is estimated. The estimated hydraulic conductivity is compared to a selected threshold. The selected threshold is based on pumping parameters and pumping pressure behavior of at least one pumped hydraulic fracture treatment. A warning signal is generated when the hydraulic conductivity is below the selected threshold and/or the determined polarity indicates a closed boundary condition so that the treatment may be adjusted to avoid screenouts and other operational and treatment issues.
A method for characterizing a sand-pack or gravel-pack in a subsurface formation includes inducing a pressure change to induce tube waves in fluid in a well drilled through the subsurface formation. At a location proximate to a wellhead at least one of pressure and a time derivative of pressure in the well is measured for a selected length of time. At least one of a physical parameter and a change in the physical parameter with respect to time, of the sand-pack or gravel-pack, is determined using the measured pressure and/or the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
A method and a system to determine fracture properties during standard operations and injection tests. Fracture compliance, fracture closure pressure, and perforation friction can be determined using a combination of acoustic data, pressure decay data, and wellbore models. A method of automating and adjusting fracture design in real-time. A method and system to recover active, single active pulse data from a background noise dataset.
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a borehole drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the borehole for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the borehole and its real-time implementation.
E21B 47/095 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes by detecting acoustic anomalies, e.g. using mud-pressure pulses
22.
METHOD FOR EVALUATING AND MONITORING FORMATION FRACTURE TREATMENT USING FLUID PRESSURE WAVES
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B 43/267 - Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
A method to measure fracture length and geometry/complexity from pressure decay and diffusion and near wellbore conductivity measurements with far-field conductivity estimates.
A method for characterizing a hydraulic fracture in a subsurface formation, includes inducing a pressure change in a well drilled through the subsurface formation. Pressure and/or a time derivative thereof is measured at a location proximate to a wellhead for a selected length of time. A conductivity of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure. A change in the determined conductivity with respect to time is determined.
G01V 99/00 - Subject matter not provided for in other groups of this subclass
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
G01V 1/40 - Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging
A method to measure fracture length and geometry/complexity from pressure decay and diffusion and near wellbore conductivity measurements with far-field conductivity estimates.
Method for fracture activity monitoring and pressure wave resonance analyses for estimating geophysical parameters of hydraulic fractures using fracture waves
A method for characterizing a hydraulic fracture treatment both operationally and in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the well for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method of evaluating hydraulic fracturing treatment and operations by monitoring resonant structures present while fracturing. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the wellbore and its real-time implementation.
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B 43/267 - Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a borehole drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the borehole for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the borehole and its real-time implementation.
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B 43/26 - Methods for stimulating production by forming crevices or fractures
G01V 1/40 - Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging
A method for characterizing a sand-pack or gravel-pack in a subsurface formation includes inducing a pressure change to induce tube waves in fluid in a well drilled through the subsurface formation. At a location proximate to a wellhead at least one of pressure and a time derivative of pressure in the well is measured for a selected length of time. At least one of a physical parameter and a change in the physical parameter with respect to time, of the sand-pack or gravel-pack, is determined using the measured pressure and/or the time derivative of pressure.
E21B 47/12 - Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
E21B 47/14 - Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
G01V 1/28 - Processing seismic data, e.g. analysis, for interpretation, for correction
A method for evaluating a wellbore treatment includes inducing an acoustic wave in the wellbore prior to treatment. Acoustic energy propagating as pressure waves in the wellbore is detected. A formation in fluid communication with the wellbore is treated. The inducing an acoustic wave and detecting acoustic energy are repeated. A characteristic of the treatment is determined based on differences between the detected acoustic energy prior to the treating and at the end of the treating. In some embodiments, the observed differences are then also compared to differences observed in prior treatment stages to assess benefit of changes to treatment design. In some embodiments, the treatment design parameters are continuously iterated, adjusted, and improved to maximize the contribution to production of all subsequent stages in same or any other well.
E21B 47/18 - Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves through the well fluid
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
31.
METHOD FOR EVALUATING AND MONITORING FORMATION FRACTURE TREATMENT USING FLUID PRESSURE WAVES
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
32.
METHOD FOR EVALUATING AND MONITORING FORMATION FRACTURE TREATMENT USING FLUID PRESSURE WAVES
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
33.
METHOD FOR EVALUATING AND MONITORING FORMATION FRACTURE TREATMENT USING FLUID PRESSURE WAVES
A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and pressure time derivative are measured in or at a location proximate to a wellhead for a selected length of time. At least one of a physical parameter, a time derivative, and a change in the parameter with respect to time of the physical parameter of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
34.
METHOD FOR EVALUATING AND MONITORING FORMATION FRACTURE TREATMENT CLOSURE RATES AND PRESSURES USING FLUID PRESSURE WAVES
A method for characterizing a hydraulic fracture in a subsurface formation, includes inducing a pressure change in a well drilled through the subsurface formation. Pressure and/or a time derivative thereof is measured at a location proximate to a wellhead for a selected length of time. A conductivity of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure. A change in the determined conductivity with respect to time is determined.
E21B 47/01 - Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
G01V 99/00 - Subject matter not provided for in other groups of this subclass
G01N 15/08 - Investigating permeability, pore volume, or surface area of porous materials
35.
METHOD FOR FRACTURING ACTIVITY AND INTENSITY MONITORING AND PRESSURE WAVE RESONANCE ANALYSIS
A method for characterizing a hydraulic fracture treatment both operationally and in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the well for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method of evaluating hydraulic fracturing treatment and operations by monitoring resonant structures present while fracturing. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the wellbore and its real-time implementation.
A method for characterizing a hydraulic fracture in a subsurface formation, includes inducing a pressure change in a well drilled through the subsurface formation. Pressure and/or a time derivative thereof is measured at a location proximate to a wellhead for a selected length of time. A conductivity of at least one fracture is determined using the measured at least one of pressure and the time derivative of pressure. A change in the determined conductivity with respect to time is determined.
E21B 49/00 - Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
G01N 15/08 - Investigating permeability, pore volume, or surface area of porous materials
G01V 99/00 - Subject matter not provided for in other groups of this subclass
37.
METHOD FOR FRACTURING ACTIVITY AND INTENSITY MONITORING AND PRESSURE WAVE RESONANCE ANALYSIS
A method for characterizing a hydraulic fracture treatment both operationally and in a subsurface formation includes inducing a pressure change in a well drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the well for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method of evaluating hydraulic fracturing treatment and operations by monitoring resonant structures present while fracturing. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the wellbore and its real-time implementation.
A method for evaluating a wellbore treatment includes inducing an acoustic wave in the wellbore prior to treatment. Acoustic energy propagating as pressure waves in the wellbore is detected. A formation in fluid communication with the wellbore is treated. The inducing an acoustic wave and detecting acoustic energy are repeated. A characteristic of the treatment is determined based on differences between the detected acoustic energy prior to the treating and at the end of the treating. In some embodiments, the observed differences are then also compared to differences observed in prior treatment stages to assess benefit of changes to treatment design. In some embodiments, the treatment design parameters are continuously iterated, adjusted, and improved to maximize the contribution to production of all subsequent stages in same or any other well.
A method for evaluating a wellbore treatment includes inducing an acoustic wave in the wellbore prior to treatment. Acoustic energy propagating as pressure waves in the wellbore is detected. A formation in fluid communication with the wellbore is treated. The inducing an acoustic wave and detecting acoustic energy are repeated. A characteristic of the treatment is determined based on differences between the detected acoustic energy prior to the treating and at the end of the treating. In some embodiments, the observed differences are then also compared to differences observed in prior treatment stages to assess benefit of changes to treatment design. In some embodiments, the treatment design parameters are continuously iterated, adjusted, and improved to maximize the contribution to production of all subsequent stages in same or any other well.
A method for characterizing a subsurface fluid reservoir includes inducing a pressure wave in a first well traversing the subsurface reservoir. A pressure wave in at least a second well traversing the subsurface reservoir is detected. The detected pressure wave results from conversion of a tube wave generated by the pressure wave in the first well into guided waves. The pressure wave in the at least a second well is generated by conversion of the guided waves arriving at the at least a second well. A guided (K) wave travel time from the first well to the at least a second well is determined and a physical property of the subsurface fluid reservoir is determined from the K-wave travel time.
G01V 1/133 - Generating seismic energy using fluidic driving means, e.g. using highly pressurised fluids
G01V 1/137 - Generating seismic energy using fluidic driving means, e.g. using highly pressurised fluids which fluids escape from the generator in a pulsating manner, e.g. for generating bursts
G01V 1/36 - Effecting static or dynamic corrections on records, e.g. correcting spread; Correlating seismic signals; Eliminating effects of unwanted energy
G01V 1/42 - Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging using generators in one well and receivers elsewhere or vice-versa
