Abstract: The present invention relates to methods of fracturing a subterranean formation including the step of pumping at least one device actively transmitting data that provide information on the device position, and further comprising the step of assessing the fracture geometry based on the positions of said at least one device or pumping metallic elements, preferably as proppant agents, and further locating the position of said metallic elements with a tool selected from the group consisting of magnetometers, resistivity tools, electromagnetic devices and ultra-long arrays of electrodes. The invention allows monitoring of the fracture geometry and proppant placement.

Abstract: The treatment well tiltmeter system comprises one or more tiltmeter assemblies which are located within an active treatment well. The treatment well tiltmeter system provides data from the downhole tiltmeters, and can be used to map hydraulic fracture growth or other subsurface processes from the collected downhole tilt data versus time. The system provides tilt data inversion of data from each of the treatment well tiltmeter assemblies, and provides isolation of data signals from noise associated with the treatment well environment. As well, the treatment well tiltmeter system provides geomechanical modeling for treatment well processes.

Abstract: Compositions and methods for determining the source of treatment fluids being produced from a production formation having multiple zones.

Abstract: A method for optimally orienting perforations in a subterranean formation is disclosed, the optimization process being based on establishing the orientation of bedding planes in the formation and, where applicable, hole size effects while determining an orientation of the perforation that balances the stress concentration along the circumference of the cross-section between perforation and bedding plane in further improvements of the method inhomogeneous stress distributions and permeability are included into the optimization process.

Abstract: A system and method for the measurement of the stresses and pressure perturbations surrounding a well, and a system for computing the optimum location for initiating a hydraulic stress fracture. The technique includes using sensors attached to the wellbore casing connected to a data analyzer. The analyzer is capable of analyzing the stresses on the well system. Using an inverse problem framework for an open-hole situation, the far field stresses and well departure angle are determined once the pressure perturbations and stresses are measured on the wellbore casing. The number of wellbore measurements needed for the inverse problem solution also is determined. The technique is also capable of determining the optimal location for inducing a hydraulic fracture, the effect of noisy measurements on the accuracy of the results, and assessing the quality of a bond between a casing and a sealant.

Abstract: A method for assessing the fracture pressure closure is proposed. This method includes first injecting a fluid into the formation at a first generally constant rate Q to create a fracture, and then, dropping the pumping rate to significantly smaller feed rate q so that the volume of the fracture becomes constant, in other words. As the fracture volume becomes constant at equilibrium, the well is shut-in. The wellbore pressure is monitored and the closure pressure is determined from the analysis of the wellbore pressure using a time-function of the dimensionless “shut-in” time, defined as the ratio of time since shutting to pumping time. This method provides a way of estimating the friction component of the monitored wellbore pressure due to the fracture tortuosity and friction.

Abstract: Tracing hydraulic fractures, stimulations, selective cement jobs, etc. in oil and gas wells includes introducing into a well in a zone of interest a plurality of radio frequency transmitting elements each having an identification, moving in the well a reader tool operative for transmitting radio waves so as to generate and send a radio frequency signal for activating the radio frequency transmitting elements and thereafter to receive a signal returned from the corresponding radio frequency transmitting elements together with the identification of each radio frequency transmitting element, and analyzing data related to the sending of the radio frequency signal from the reader tool to the radio frequency transmitting element and the receiving of the radio frequency signal from the radio frequency transmitting elements with the identification of the radio frequency transmitting elements, so as to trace a corresponding hydraulic fracture, stimulation, selective cement job, etc., in the zone of interest.

Abstract: A method for determining the characteristics of a subterranean formation penetrated by an existing or drilled well is disclosed. The method uses a mathematical model to estimate formation parameters as fluid exits the formation through a hole and into the wellbore or tool. The model may be adapted to wells having a perforation extending from the wellbore into the formation by mathematically adjusting the perforation to the hole of the mathematical model. The formation properties may be estimated by mathematically eliminating the perforation and replacing it with an enlarged hole radius to simulate the mathematical model.

Abstract: A method for aligning measurements of a hostile environment includes synchronizing at least two clocks, wherein at least a first clock is in the hostile environment, measuring characteristics of the hostile environment, aligning time domain curves of the collected measurements, correlating the curves using one or more events recorded by each clock, and correcting the curves by adding one or more time offsets. The offsets may be added to a found resent event or at other locations on the time domain curve. A second clock may be located outside the hostile environment or within a same or similar hostile environment. The collecting the measurements may be taken by a first measurement tool in a first device near the first clock and in at least a second device coupled to a second clock.

Abstract: A method and apparatus for initiating an azimuth controlled vertical hydraulic fracture in unconsolidated and weakly cemented soils and sediments using active resistivity to monitor and control the fracture initiation and propagation. Separate or overlapping treatment walls and containment barriers can be created by controlling and monitoring the propagation of fractures in the subsurface. A fracture fluid is injected into a well bore to initiate and propagate a vertical azimuth controlled fracture. The fracture fluid is energized to conduct electrical current while the fracture propagates through the ground. A series of electrical resistivity monitors measure the electrical conductivity of the fracture fluid in real time against the background conductivity of the formation.

Abstract: Methods are disclosed for hydraulic fracturing of subterranean reservoir formations using various combinations of gelled fluid, nitrogen, and carbon dioxide base components, in association with proppant and other additives. Selected base components are pumped down a wellbore tubing while other selected base components are simultaneously pumped down the wellbore tubing-casing annulus for downhole mixing into a composite fracturing fluid in the downhole region of the wellbore proximal to the reservoir objective. Thereby, changes may be timely effected in the composite fluid composition and fluid properties, substantially immediately prior to the composite fluid entering the formation. Such real-time modifications may be effected to readily preempt screenout occurrences and may facilitate composite fluid compositions which otherwise are frequently undesirable to pump from the surface. Such composite fluid combinations include components phases of each of carbon dioxide, nitrogen and a base fluid.

Abstract: A method and apparatus for performing sand control using fracturing is described. A curve is defined that correlates the percentage of flow through out-of-phase perforations (those perforations not aligned with fractures) with the fracture conductivity over formation permeability. Given a desired production flow, formation conductivity may be defined. This allows the well operator to perform the proper fracturing operation to achieve the desired fracture conductivity. Alternatively, after a well has been fractured, and sand production is observed, a critical flow rate and the corresponding drawdown pressure can be calculated to prevent sand production.

Abstract: The closure pressure (Pc) of a fracture generated in a subterranean formation is determined by creating a fracture in the formation, permitting the fracture to close, and performing post-closure pulse testing. The method is particularly applicable to soft formations (i.e. those having a rock plain-strain modulus (E′) of less than 800,000 psi).

Abstract: The invention is a method and apparatus for initiating an azimuth controlled vertical hydraulic fracture in unconsolidated and weakly cemented soils and sediments using active resistivity to monitor and control the fracture initiation and propagation. Separate or overlapping treatment walls and containment barriers can be created by controlling and monitoring the propagation of fractures in the subsurface. A fracture fluid is injected into a well bore to initiate and propagate a vertical azimuth controlled fracture. The fracture fluid is energized to conduct electrical current while the fracture propagates through the ground. A series of electrical resistivity monitors measure the electrical conductivity of the fracture fluid in real time against the background conductivity of the formation.

Abstract: The invention provides a method of detecting, at the surface, the occurrence of torsional vibration in a bottomhole assembly mounted on the drill string of a rotary drilling system. The method includes the steps of: ascertaining natural frequencies of torsional vibration of the bottomhole assembly prior to drilling, and noting at least one reference frequency for an integer wavelength mode of torsional vibration of the bottomhole assembly. During subsequent drilling, the drill string mean square torque at the surface is monitored for a bandwidth around the reference frequency. It is found that peaks in the mean square torque, close to the reference frequency, are indicative of the occurrence of torsional vibration in the bottomhole assembly.

Abstract: A method for forming a fracture in a viscous oil subterranean formation wherein a data-fracturing operation is carried out to first determine the “leak-off” rate for the formation and then the formation is fractured with a slurry wherein the liquid from the slurry will leak into the formation at the predetermined leak-off rate to thereby provide fractures of a desired length necessary in sand control or the like. In accordance with the present invention, the formation is treated before both the data-fracturing operation and the subsequent fracturing operation with a treatment fluid (e.g. diesel) which will interact with the viscous oil to reduce its viscosity so that the fracturing fluid can readily leak into the formation.

Abstract: A method and apparatus for initiating an azimuth controlled vertical hydraulic fracture in unconsolidated and weakly cemented soils and sediments using active resistivity to monitor and control the fracture initiation and propagation. Separate or overlapping treatment walls and containment barriers can be created by controlling and monitoring the propagation of fractures in the subsurface. A fracture fluid is injected into a well bore to initiate and propagate a vertical azimuth controlled fracture. The fracture fluid is energized to conduct electrical current while the fracture propagates through the ground. A series of electrical resistivity monitors measure the electrical conductivity of the fracture fluid in real time against the background conductivity of the formation.

Abstract: This invention provides a method for designing a multiple-stage ball sealer-diverted fracture treatment so that only one set of perforations is fractured by each stage of fluid pumped. It further provides a method for predicting the sequencing in which perforated intervals will fracture during treatment.