Step Into Full 3D Modelingwith GOHFER 9.1

R. D. Barree

February 20, 2017

Barree & Associates

© 2017

GOHFER 9.0 Capabilities

• Multiple wells, including vertical and horizontal, in the same model

• Fracture stress-shadow interference between each fracture and stage, on each well

• Multi-layer completions, zipper-fracs, and offset depletion effects

• Full 3D geo-mechanical earth model input (from Petrel GSLIB file)

• Optional input of 2D surface map with reference well logs

• Geo-steering of laterals and engineered completions

• Full processing of log or “core” from 3D earth model

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Example 3D Input FilePETREL: Properties

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i_index unit1 scale1

j_index unit1 scale1

k_index unit1 scale1

x_coord unit1 scale1

y_coord unit1 scale1

z_coord unit1 scale1

Zones unit1 scale1

APC_RT unit1 scale1

C2_PHIT unit1 scale1

C2_SWT unit1 scale1

K_calc_C unit1 scale1

K_calc_C_Vert unit1 scale1

APC_POIS_SYN unit1 scale1

APC_YOUNGS_MOD_SYN unit1 scale1

APC_TOC unit1 scale1

APC_VCARB unit1 scale1

APC_VCL unit1 scale1

APC_VPYR unit1 scale1

APC_VQTZ unit1 scale1

NetPay unit1 scale1

PorePressure unit1 scale1

2 1 99 1705598.90085963 14568605.60489428 -2594.72659302 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.281046 4.914100 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

3 1 99 1705628.90920820 14568605.60635388 -2595.11215210 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.281249 4.882559 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

4 1 99 1705658.91694500 14568605.60775768 -2595.49203491 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.280853 4.940229 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

5 1 99 1705688.92386640 14568605.60899245 -2595.86874390 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.281249 5.029984 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

6 1 99 1705718.93012547 14568605.60993182 -2596.24710083 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.282570 4.977376 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

7 1 99 1705748.93577896 14568605.61070168 -2596.62396240 13.000000 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 0.281739 4.869569 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00 -9999.00

Standard GSLIB output from Petrel, with cell locations.

Any list of spatially distributed variables can be used to generate necessary

grid variables.

GSLIB and GOHFER grid spacing do not need to be consistent. Data can be

sampled at any user-defined frequency.

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Example Total Stress Imported from 3D Model

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Full 3D Geo-Model Viewer

• See what is in the “black box”

• Cut sections out of any size imported 3D geo-cellular model for use in te simulation of a single pad

• Examine all input variables in the geo-model, layer by layer, to evaluate validity of their distribution in space, continuity, and magnitude

• Extract selected variables for use in the simulation

• Extract individual 2D structural surfaces, or use the entire 3D space

• Process and generate synthetic sonic logs, mechanical and reservoir properties, in 3D space from available input data

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Map View for Pad Layout

Any layer in the 3D space

can be displayed as a map

view.

Reference well can be

anywhere within the map.

Green lines show direction

of maximum horizontal

stress and positions of

transverse grids (for manual

drawing of properties).

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Design Template for Pad Development

• Set up perforation cluster spacing, shot density and perf geometry for a group of stages on any and all wells on a pad

• Input a single design pump schedule to be applied to all selected stages and wells, for “factory mode” completions

• Ability to define different schedules and perforation placement to multiple design groups, by stage or by individual well

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Graphical Input of Stage Shadowing

• Quickly and easily identify the chronological order of all frac stages on a pad

• Automatically re-order all stages to run in batch mode in the correct order

• Separate multiple stage shadow groups, if separate well pads or groups are treated at different times

• Process entire groups in batch model simultaneously

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Offset Well Depletion Effect on Total Stress

Any grid property can be displayed in rotatable 3D view, with cross-sections at

any point on any well. Note one fault displayed in the section.

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Evolution of Fracture Geometry with Offset Depletion

Treating green well:

Early pad fluid hits offset depleted well, before

significant geometry is developed at the

treatment well.

Fracture begins to develop

at the treatment well after

pressurizing depleted

area.

Fracture height and concentration

develop at new treatment well near

end of job.

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Import of Pore-Pressure Depletion Models

• Import a fully 3D pore pressure space, in GSLIB format, using the same coordinate space as the surface map or 3D Geo-model

• Take 3D pore pressure distribution directly from numerical reservoir simulators at any time, to model parent-child interference

• Overwrite existing pore pressure space, and automatically recalculate closure stress, extension pressure, and fracture geometry resulting from the new pressure distribution

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Zipper-Frac Interference

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Interference (zipper frac) between wells 1 and 4 cause fracture asymmetry.

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Interference Causing Height Growth

Later fracture treatment on well 2, confined by wells 1 and 4, drives height

growth. Timing between fracs is critical.

142

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Any Number of Well Layers, Wells, and Stages can be Modeled

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With Great Power Comes Great Responsibility

All wellhead locations,

surveys, surface elevations,

and coordinate systems

must be specified, and must

be consistent.

Metric projects are assumed

to have 3D space in UTM

coordinates.

“Oilfield” projects are

expected in State-Plane

coordinates.

Complete earth-space

models are preferred.

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Complex Geology, Well Trajectory, and Completion Choices

Reservoir and

mechanical properties

are computed from

whatever data is

supplied in the 3D

model input, and

distributed in space.

All functions in the

current GOHFER LAS

processing can be

applied to the 3D

model imported data.

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Full File Export Capability

• Export all processed grid, reservoir, and geomechanical data in full 3D in GSLIB format

• Export all fracture grid state variables at any time during the simulation, for each fracture stage, including proppant concentration, effective conductivity, or any other property

• Export all combined fracture properties for the entire pad, all wells and all stages, in a single GSLIB file for import to other simulators

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Fracture and Stage Stress Shadowing

Stress interference within a frac stage, and between stages, on

multiple wells, is modeled correctly. Asymmetric and non-

orthogonal fractures are simulated.

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Strongly Interacting Fractures on Multiple Wells

Both longitudinal and

transverse, asymmetric and

off-angle fractures are

simulated in simultaneous

development and

interaction.

Order of treatments, and

timing between treatments

affects the results.

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Enter the Fourth Dimension• Timing of “zipper fracs” between wells or stages, allowing closure and

relaxation of induced pore pressure and strain, can be simulated

• Time-dependent evolution of pore pressure and coupled stress fields can be modeled

• Pore pressure depletion in offset wells significantly affects treatment of infill wells

• Effectiveness of “protection fracs” and injection into existing wells can be evaluated

• Direct import of 3D pore pressure distribution from reservoir simulators, into the model space, should be possible if coordinate systems overlap

• GOHFER supports output of fracture geometry and conductivity profiles for all fracture planes, on all wells, in CMG and GSLIB file formats

• Micro-seismic event locations can be imported and displayed on 3D outputs, along with generated fracture geometries

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Get Yourself Out Of the Mangrove Swamp

Don’t be stuck with pseudo-anything in your

models.

Full 3D fracture geometry modeling with

GOHFER.

Simultaneous transverse and longitudinal

fractures, with full stress-interaction.

Complex fracture height growth resulting from

interference.

Full coupling with Petrel and numerical

reservoir simulators.

Industry leading proppant and fluid rheology

models and databases.

Complete production forecasting, economic

analysis, and production rate-transient and

decline analysis.

Computation of reservoir and mechanical

properties from logs or 3D model input.

Inclusion of micro-seismic results.