40 results about "Fracture geometry" patented technology

A method of evaluating the geometry of a hydraulic fracture in a rock formation comprises the steps of: obtaining measured values of electric and/or magnetic fields induced by the forward or back propagation of a fracturing fluid between the fracture and the rock formation; and determining the geometry of the fracture from the measured values.

Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

A method for determining fracture geometry of a subterranean formation from radiation emitted from a fracture in the formation, including measuring gamma-radiation emitted from the fracture; subtracting background radiation from the measured gamma-radiation to obtain a peak-energy measurement; comparing the peak-energy measurement with a gamma-ray transport/spectrometer response model; and determining formation fracture geometry of the fracture in accordance with values associated with the response model.

Methods for determining hydraulic fracture geometry and/or areal extent of an area of interest in a reservoir, are provided. An exemplary method includes isolating downhole acoustic receiver equipment in a lower portion of a first wellbore from fracturing operations located in a second wellbore connected to the first wellbore. Communications between surface equipment in the downhole acoustic receiver equipment is provided through a communications conduit bypass that permits well operations in the second wellbore without interfering with communications between the surface equipment and the downhole acoustic receiver equipment.

Prior to a hydraulic fracturing treatment, the estimated fracture length may be estimated with knowledge of certain physical properties of the proppant and transport fluid such as fluid viscosity, proppant size and specific gravity of the transport slurry as well as fracture geometry and the treatment injection rate. The estimated fracture length may be determined by the equation:

(D_PST)^B=q_i×(1/A)×C_TRANS×(d²_prop)×(1/μ_fluid)×(ΔSG_PS)   (I)

wherein:

• • D_PST is thus the estimated propped fracture length;
  • B is the exponent from the Power Law equation describing the transport slurry velocity vs. distance for the fracture geometry;
  • q_i is the injection rate per foot of injection height, bpm/ft.; and
  • A is the multiplier from the Power Law equation describing the transport slurry velocity vs. distance for the fracture geometry;
  • C_TRANS, the transport coefficient, is the slope of the linear regression of the I_SP vs. MHV_ST.

d_prop is the median proppant diameter, in mm.;

• • μ_fluid is the apparent viscosity of the transport fluid, in cP; and
  • Δ SG_PS is SG_prop−SG_fluid, SG_prop being the specific gravity of the proppant and
  • SG_fluid being the specific gravity of the transport fluid.

The minimum horizontal flow velocity, MHV_ST, for transport of the transport slurry based upon the terminal settling velocity of the proppant, V_t, may be determined in accordance with Equation (II):

MHV_ST, =V_t×10   (II)

Via rearrangements of the same derived equations, a model for optimizing the transport fluid, proppant, and/or treating parameters necessary to achieve a desired propped fracture length may further be determined.

A method is given of fracturing a subterranean formation including the step of a) 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 b) 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, and further comprising the step of assessing the fracture geometry based on the positions of said metallic elements. The method allows monitoring of the fracture geometry and proppant placement.

The present invention discloses a frost heave force model of a rock tunnel based on a rock-water-ice force in-situ test. A pore water pressure gauge, an earth pressure box, and a multi-point platinumresistance temperature sensor are used in a combination manner to perform a frost heave force in-situ test on fractured rocks, the temporal and spatial evolution laws of the fissure water pressure, the ice pressure, and the surrounding rock pressure before and after freezing of the fractured rocks are obtained, and theoretical model calculation results, in-situ test results, and existing researchresults are compared and analyzed. According to the frost heave force model of the rock tunnel based on the rock-water-ice force in-situ test provided by the present invention, in-situ testing on siteis used, the test method is innovated outside the previous test system mainly containing the freeze-thaw cycle mechanics test of fractured rock masses, the lack of measurement methods is compensated,the frost heave force in natural water-containing cracks is obtained, and starting from macro and engineering applications, the discussion of the meso-structure and fracture geometry of fractured rocks is avoided; the general area of low-temperature water-ice phase transition and the direction of water migration are considered; and the frost heave force model of the rock tunnel based on the rock-water-ice force in-situ test provided by the present invention will provide a reference for similar projects of the currently developed Sichuan-Tibet Highway.

A method for optimizing well spacing for a multi-well pad which includes a first group of wells and a second group of wells is provided. The method includes the steps of: creating a fracture in a stage in a first well in the first group of wells; isolating a next stage in said first well in the first group of wells from said stage; creating a fracture in said next stage in the first well in the first group after the step of isolating; measuring a pressure by using a pressure gauge in direct fluid communication with said next stage in the first well in the first group of wells; creating a fracture in one or more stages in a well in the second group of wells in a manner such that the fracture in the well in the second group of wells induces the pressure measured in the first well to change; and recording the pressure change in the next stage of the first well.

Monitoring and diagnosing completion during hydraulic fracturing operations provides insights into the fracture geometry, inter-well frac hits and connectivity. Conventional monitoring methods (microseismic, borehole gauges, tracers, etc.) can provide a range of information about the stimulated rock volume but may often be limited in detail or clouded by uncertainty. Utilization of DAS as a fracture monitoring tool is growing, however most of the applications have been limited to acoustic frequency bands of the DAS recorded signal. In this paper, we demonstrate some examples of using the low-frequency band of Distributed Acoustic Sensing (DAS) signal to constrain hydraulic fracture geometry. DAS data were acquired in both offset horizontal and vertical monitor wells. In horizontal wells, DAS data records formation strain perturbation due to fracture propagation. Events like fracture opening and closing, stress shadow creation and relaxation, ball seat and plug isolation can be clearly identified. In vertical wells, DAS response agrees well with co-located pressure and temperature gauges, and illuminates the vertical extent of hydraulic fractures. DAS data in the low-frequency band is a powerful attribute to monitor small strain and temperature perturbation in or near the monitor wells. With different fibered monitor well design, the far-field fracture length, height, width, and density can be accurately measured using cross-well DAS observations.

Articles and methods utilizing radiation susceptible materials are provided herein. In one aspect, a proppant, a treatment fluid, or both, may comprise a radiation susceptible material. In another aspect, a method is provided comprising disposing in a formation fracture, a proppant and/or a treatment fluid that comprises a radiation susceptible material, irradiating the radiation susceptible material with neutrons, measuring gamma-radiation emitted from the radiation susceptible material in a single pass, and determining formation fracture height from the measured gamma-radiation. The single-pass may be a continuous process or a periodic process.

A method for treating a subterranean formation utilizing a composition having a plurality of shrinkable materials. The method of treatment may include providing a hydraulic fracture into the subterranean formation, and injecting a slurry having a plurality of shrinkable materials into a far field. The shrinkable materials may shrink once a threshold is reached.

Method for characterizing subterranean formation is described. One method involves simulating a poroelastic pressure response of known fracture geometry utilizing a geomechanical model to generate a simulated poroelastic pressure response. Compiling a database of simulated poroelastic pressure responses. Measuring a poroelastic pressure response of the subterranean formation during a hydraulic fracturing operation to generate a measured poroelastic pressure response. Identifying a closest simulated poroelastic pressure response in the library of simulated poroelastic pressure response. Estimating a geometrical parameter of a fracture or fractures in the subterranean formation based on the closest simulated poroelastic pressure response

The disclosure presents a technique to generate a fracture model using a differential stress map and model inputs. The technique simulates the fracture model using fracture fronts, initiated at perforations of a perforation stage of a hydraulic fracturing (HF) wellbore. Each fracture front is evaluated using a propagation step of a fracture model process. Using the relative differential stress states, a fracture pattern is composited to the fracture model. At each propagation step, the total energy available from the simulated fluid being pumped into the wellbore location is reduced by the amount necessary to generate the computed fractures. Once the remaining energy is reduced to a level where no further fractures can be created, or if a map boundary is encountered, the fracture model process terminates. The generated fracture model can be communicated to update HF job plans, wellbore placements, and other uses of the fracture model.

A method of performing a fracture operation is provided at a wellsite. The wellsite is positioned about a subterranean formation having a wellbore therethrough and a complex fracture network therein. The complex fracture network includes natural fractures, and the wellsite stimulated by injection of an injection fluid with proppant into the complex fracture network. The method involves generating wellsite data comprising measurements of microseismic events of the subterranean formation, modeling a hydraulic fracture network and a discrete fracture network of the complex fracture network based on the wellsite data, and performing a seismic moment operation. The method involves determining an actual seismic moment density based on the wellsite data and a predicted seismic moment density based on shear and tensile components of the simulated hydraulic fracture network, and calibrating the discrete fracture network based on a comparison of the predicted moment density and the actual moment density.

The invention introduces a method of calculating etching profile of acid-etched fracture system considering complex filtration media, which mainly considers dynamic filtration caused by natural fractures and acid-etched wormholes in acid fracturing, calculates the above filtration process by a numerical method, and finally calculates acid etching profile of acid-etched fracture system based on acid concentration profile. Calculation equations include fluid pressure in natural fractures, filtration velocity in natural fractures, fracture geometry of hydraulic fractures, fluid pressure in matrix rock, acid concentration profile in natural fractures and hydraulic fractures, acid etching width in hydraulic fractures and natural fractures, and length of acid-etched wormhole, etc. The invention is reliable in principle and efficient in calculation, which is also beneficial to accurately calculating fracture etching profiles of acid fracturing in naturally-fractured reservoirs, improving the accuracy of optimizing acid fracturing treatment parameters, and providing guiding significance for acid fracturing optimization of naturally-fractured carbonate reservoirs.

A method of mapping subsurface fracture geometry below a surface of the ground includes two independently powered systems, namely a plurality of sensors distributed through a hole in the subsurface and a downhole tool to facilitate reception and transmission of signal data from the plurality of sensors. The sensors are distributed into fissures within formations that have been hydraulically fractured. The sensors send signal data to the downhole tool for transmission to a unit on the surface. The signal data permits for the mapping of the fissures within the fractured formations.