Halliburton Energy Services, Inc.

Avi Lin

Dinesh Ananda Shetty

Jianfu Ma

Srinath Madasu

Harold Grayson Walters

Baidurja Ray

Joshua Lane Camp

Jie Bai

Pandurang Manohar Kulkarni

Dylan Matthew Copeland

Hongfei Wu

Kenneth E Williams

Uma Balakrishnan

Brian A Freno

An illustrative hydraulic fracturing flow simulation method includes: identifying a network of fractures within a formation rock matrix; modeling each fracture in the network as fluid flow path having discrete points at which a fluid pressure is determined; representing the rock matrix with discrete nodes at which a fluid-solid interaction force is determined, each said discrete node being associated with multiple discrete points along a fluid flow path; deriving the fluid-solid interaction force for each node from the fluid pressure at the associated discrete points; estimating an extent of fracture propagation based in part on the fluid-solid interaction forces; and displaying a visual representation of the fracture propagation extent. The deriving includes: obtaining an analytic integral of the fluid pressure as modified by a weighting function for each interval between adjacent ones of the associated discrete points; evaluating the analytic integrals for each interval to obtain contributions; and summing the contributions.

Fracture network fluid flow simulation with enhanced fluid-solid interaction force determination

A hydraulic fracturing flow simulation method includes identifying one or more reservoir layers contacted by a wellbore, the reservoir layers including a network of fractures. The method further includes determining a current network state that includes flow parameter values at discrete points arranged one-dimensionally along the wellbore and at discrete points arranged one-dimensionally along each fracture, the flow parameter values including concentrations of multiple proppant types or sizes. The method further includes constructing a set of linear equations for deriving a subsequent network state from the current network state while accounting for interaction and settling of the multiple proppant types or sizes. The method further includes repeatedly solving the set of linear equations to obtain a sequence of subsequent network states. The method further includes displaying the time-dependent spatial distribution.

Time-dependent spatial distribution of multiple proppant types or sizes in a fracture network

An illustrative domain-adaptive simulator includes: a data acquisition module, a simulator module, and a visualization module. The data acquisition module acquires measurements of a physical system. The simulator module provides a series of states for the physical system, the series including at least a current state and a subsequent state, wherein as part of said providing, the simulator module implements a method that includes: (a) constructing a modeled domain for the system; (b) determining a domain of influence within the modeled domain; (c) generating a linear set of equations to derive the subsequent state from the current state, the linear set of equations excluding a region of the modeled domain outside the domain of influence; and (d) deriving the subsequent state from the linear set of equations. The visualization module displays the series of states.

Simulators and simulation methods using adaptive domains

A hydraulic fracturing flow simulation method includes identifying a discrete fracture network that partitions a reservoir into porous rock blocks. The method further includes determining a current network state that includes flow parameter values at discrete points arranged one-dimensionally along the fractures in said network. The method further includes constructing a set of linear equations for deriving a subsequent network state from the current state. The method further includes repeatedly solving the set of linear equations to obtain a sequence of subsequent network states, the sequence embodying a time-dependent spatial distribution of at least one flow parameter, said flow parameter comprising a proppant volume fraction. The method further includes displaying the time-dependent spatial distribution.

Time-dependent spatial distribution of proppant effects in a discrete fracture network

In some aspects, a one-dimensional proppant transport flow model represents flow of a proppant-fluid mixture in a subterranean region. The one-dimensional proppant transport flow model includes a fluid momentum conservation model and a proppant bed momentum conservation model that account for viscoelastic effects of the proppant-fluid mixture. The one-dimensional proppant transport flow model may also include a proppant momentum conservation model. In some cases the one-dimensional proppant transport flow model may account for any of settling and resuspension of a proppant bed and interphase momentum transfer between the proppant, proppant bed, and the fluid.

Modelling of fluid elasticity effects on proppant dynamics

An illustrative hydraulic fracturing flow simulation system includes: a data acquisition module collecting measurements from a subterranean formation; a processing module implementing a hydraulic fracturing simulation method; and a visualization module that displays the time-dependent spatial distribution. The simulation method includes: deriving from the measurements a network of fractures having junctions where two or more fractures intersect; ordering a set of corner points associated with each junction; calculating a junction area from each set of corner points; determining a current state that includes flow parameter values at discrete points arranged along the fractures in said network; constructing a set of linear equations for deriving a subsequent state from the current state while accounting for said junction areas; and repeatedly solving the set of linear equations to obtain a sequence of subsequent states, the sequence embodying a time-dependent spatial distribution of at least one flow parameter.

Fracture network fluid flow simulation with junction area modeling

An illustrative domain-adaptive hydraulic fracturing simulator includes: a data acquisition module, a simulator module, and a visualization module. The data acquisition module acquires measurements of a subterranean formation undergoing a hydraulic fracturing operation. The simulator module provides a series of states for a model of the subterranean formation by: (a) constructing said model from the measurements, the model representing said current state throughout a modeled domain; (b) determining a core domain of influence within the modeled domain by identifying active fractures; (c) generating a linear set of equations to derive the subsequent state from the current state, the linear set of equations including fluid flow equations for the core domain of influence and excluding fluid flow equations for a region of the modeled domain outside the core domain of influence; and (d) deriving the subsequent state from the linear set of equations. The visualization module displays the series of states.

Domain-adaptive hydraulic fracture simulators and methods

An illustrative hydraulic fracturing simulation method includes: creating an initial mesh representation of a subterranean formation, the mesh including mesh nodes; determining one or more fracture paths in the formation; for each of the one or more fracture paths, displacing a subset of the mesh nodes into alignment with the fracture path; interpolating from displacements of the aligned mesh nodes to obtain displacements for each non-aligned mesh node in the mesh, thereby obtaining a deformed mesh representation of the formation; using the deformed mesh to construct a linear set of equations representing fracture creation and propagation caused by injection of a hydraulic fracturing fluid; deriving one or more fracture path extensions from the linear set of equations; and displaying the one or more fracture paths with the one or more fracture path extensions accurately representing the fracture propagation path. The interpolation may be performed using radial basis functions.

Simulating hydraulic fracture propagation using dynamic mesh deformation

An illustrative monitoring system for a hydraulic fracturing operation includes: a data acquisition module collecting microseismic signals from a subterranean formation undergoing a hydraulic fracturing operation; a processing module implementing a monitoring method; and a visualization module that displays an estimate or prediction of fracture extent. The monitoring method implemented by the processing module includes: deriving microseismic event locations and times from the microseismic signals; fitting at least one fracture plane to the microseismic event locations; projecting each microseismic event location onto at least one fracture plane; determining a time-dependent distribution of the projected microseismic event locations; calculating one or more envelope parameters from the time-dependent distribution; and generating an estimate or prediction of fracture extent using the or more envelope parameters. The envelope parameters may include an exponent of a time-power law, and said generating may include re-fitting the fracture plane if the exponent isn't approximately one-half.

Systems and methods deriving hydraulic fracture growth from microseismicity analysis

An illustrative formation flow simulation method includes: measuring horizontal and vertical permeability of at least one bed in a formation penetrated by a vertical borehole; representing the borehole as a linear, discretized borehole flow path; representing the formation as a plurality of horizontal layers, each layer of the plurality of horizontal layers being represented as a linear, discretized layer flow path; constructing a current state vector having values of flow parameters for the discretized borehole flow path and each of the discretized layer flow paths; constructing a solution matrix embodying a set of flow equations that relate the current state vector to a subsequent state vector, the flow equations employing the measured horizontal permeability for flow along the discretized layer flow path for each layer and employing the measured vertical permeability for cross-flow to or from each layer, wherein the solution matrix, current state vector, and subsequent state vector form a linear system of equations; solving the linear system of equations to derive the subsequent state vector from the current state vector; and storing the subsequent state vector on a non-transitory information storage medium.

Simulating multi-dimensional flow with coupled one-dimensional flow paths

An illustrative hydraulic fracturing flow simulation system includes: a data acquisition module collecting measurements from a subterranean formation; a processing module implementing a hydraulic fracturing simulation; and a visualization module that displays a time-dependent spatial distribution. The implemented method includes: modeling a connected network of fractures; assigning an orientation to each fracture in the network to locate two different flow parameter types at each junction, thereby defining an arrangement of different flow parameter types spatially staggered along each fracture; capturing the arrangement as a set of linear equations for iteratively deriving a subsequent flow state from a current flow state; simulating flow through the network of fractures by repeatedly solving the set of linear equations; and determining the time-dependent spatial distribution of at least one flow component.

Fracture network fluid flow simulation with systematic fracture orientation

In accordance with embodiments of the present disclosure, a methodology may be used to computationally simulate a system of equations relating to the junction points of a dynamic fracture network (DFN). The simulation may utilize one or more efficient algorithms to perform a realistic, physically conservative, and stable coupled simulation of the DFN's complex flows. These algorithms may use assumptions based on the transient Navier-Stokes equations to perform the proppant laden flow simulation. As described in detail below, the algorithms may utilize a numerical methodology that accurately simulates a junction system of equations arising from solving the fluid and proppant flows inside individual fractures based on Navier-Stokes equations along with a proppant transport equation.

Junction models for simulating proppant transport in dynamic fracture networks

A method for improved data-driven estimation of a stimulated reservoir volume may generate an optimized surface that encloses a set of data points including microseismic event data corresponding to a treatment of a subterranean formation. A Delaunay triangulation may be performed on the set of data points to generate a set of polytopes. A Voronoi polygon may be generated about each data point and used to obtain a local density measure that is locally and adaptively determined for each data point. Based on the local density measure, polytopes in the set of polytopes may be discriminated for inclusion in the optimized surface.

Data-driven estimation of stimulated reservoir volume

In accordance with embodiments of the present disclosure, a discretization technique may be used to solve for fluid and proppant flow through a fracture within a dynamic fracture network. The discretization technique may involve performing a spatial discretization of non-linear coupled equations by integrating the equations over staggered finite control volumes. For example, the spatial discretization may involve integrating a continuity equation representing fluid flowing through the fracture over a first control volume along the length of the fracture, integrating a momentum equation representing the fluid flowing through the fracture over a second control volume that is staggered with respect to the first control volume, and integrating a proppant equation representative of the proppant flowing with the fluid through the fracture over the first control volume. The discretized equations may be used to determine a linear system of equations to simulate proppant flow through the dynamic fracture network.

Discretization scheme for simulating proppant transport in dynamic fracture networks

In accordance with some embodiments of the present disclosure, a method of modeling a downhole drilling tool is disclosed. The method may include obtaining microseismic data corresponding to a treatment of a subterranean region, the microseismic data including a microseismic event time for each of a plurality of microseismic events, and a microseismic event location for each of the plurality of microseismic events. The method may additionally include calculating a plurality of fracture planes based upon the microseismic event times, and calculating a closed boundary enclosing a first subset of the plurality of fracture planes. The method may further include identifying a microseismic supported stimulated reservoir volume (&#x3bc;SRN) for the treatment based on the closed boundary.

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Houston, TX, United States of America

Avi Lin