Attachment A
Work Statement
Unconventional Reservoir Engineering Project
(UREP)
Phase 2
October 1, 2014 – September 30, 2016
Summary
Phase 2 of the UREP Consortium will start on Oct. 1, 2014 and span until Sept. 30,
2016. The UREP Advisory Board (AB) meeting to be held on Nov. 13-14, 2014 in
Golden, Colorado will serve as the final meeting of Phase 1 and the kick-off meeting
of Phase 2. The general objective of UREP is to improve the understanding of tight
unconventional reservoirs and develop more appropriate reservoir engineering
tools and practices for these reservoirs. Phase 1 of the Consortium has already laid
the foundation for nanoporous reservoir engineering and reached important
milestones toward the development of new tools and practices. Phase 2 will
continue, fundamentally, along the directions established during Phase 1. In
addition to the theoretical and mathematical treatments started in Phase 1,
emphasis will also be put on nanofluidics experiments in Phase 2. The membership
fee for Phase 2 is $50,000/year with two-year commitment. This work statement
outlines the research objectives and directions and the time schedule of Phase 2.
Objectives and Scope
The focus of UREP is flow in tight unconventional oil and natural gas reservoirs. The
general objective is to achieve a more complete reservoir engineering
understanding and develop more appropriate reservoir engineering tools and
practices for these reservoirs. This objective covers the entire spectrum of reservoir
engineering research of nano-pore, nano-permeability, microfractured,
unconventional formations. Under scrutiny are the discerning physical
characteristics, non-Darcy flow mechanisms, overlooked capillary- and surfaceforce relationships, unaccustomed multi-phase flow concepts, and new fluid
exchange mechanisms between fractures and the rock matrix. Development of
reservoir models, analysis techniques, and prediction tools are also part of the
research spectrum. The research focus of the UREP Consortium is divided into five
project areas outlined in Table 1. The objectives of each project area are also
summarized in Table 1.
TABLE 1 – UREP Projects and Objectives
RESEARCH FOCUS
OBJECTIVES
PROJECT 1
Flow and Transport of
Hydrocarbon Fluids in NanoPorous Reservoirs
PROJECT 2
Fluid Transfer Between NanoPorous Matrix and Multi-Scale
Fractures
PROJECT 3
Production from Tight,
Fractured Formations in Close
Proximity of Source Rocks
(Liquid-Rich Reservoirs)
PROJECT 4
Simulation of Flow and
Transport in Fractured NanoPorous Reservoirs
PROJECT 5
Analysis and Prediction of
Well Performance in
Unconventional Reservoirs
Develop a more comprehensive understanding and
perception of flow and transport in nano-porous reservoir
rocks to form the basis of unconventional reservoir
engineering tools and practices. Understand mechanisms
associated with n-pore size environments
Define the interface conditions and fluid transfer
mechanisms between nano-porous matrix and fractures to
more realistically account for the contribution of ultratight, unconventional rock matrix
Define and model the support of source rocks on
production from contiguous fractured formations for the
analysis and prediction of production from liquids-rich
reservoirs
Progressively incorporate the results of the UREP research
projects and new findings into a numerical
unconventional-reservoir simulator developed by NITEC
Develop and improve models and interpretation methods
for pressure- and rate-transient data and long-term
production performance to help reservoir management
Proposed Work
Table 2 outlines the work completed during Phase 1, the research continuing into
Phase 2, and the new research to be initiated in Phase 2. The research tasks in Table
2 were established during Phase 1; the tasks and deliverables of each project area
will be reconsidered based on the level of funding (which is determined by the
number of consortium members) at the AB meetings to be held bi-annually.
Depending on the level of completion of the active projects and the volume of
funding available, extensions of the active projects will be proposed and new
projects will be initiated at the AB meetings.
TABLE 2 – UREP Research Tasks
RESEARCH FOCUS
Tasks
PROJECT 1
Flow and Transport of
Hydrocarbon Fluids in NanoPorous Reservoirs
PROJECT 2
Fluid Transfer Between NanoPorous Matrix and Multi-Scale
Fractures
PROJECT 3
Production from Tight,
Fractured Formations in Close
Proximity of Source Rocks
(Liquid-Rich Reservoirs)
PROJECT 4
Simulation of Flow and
Transport in Fractured NanoPorous Reservoirs
PROJECT 5
Analysis and Prediction of
Well Performance in
Unconventional Reservoirs
 Bubble-point suppression in pore proximity (complete)
 Condensation-point enhancement in pore proximity
(continuing into Phase 2)
 Experimental study of phase behavior in nanofluidics
(continuing into Phase 2)
 Filtration in nanopore throats (Phase 1 work is
complete/moving into experimental phase)
 Anomalous diffusion in tight, fractured, unconventional
reservoirs (continuing into Phase 2)
 Numerical modeling of anomalous diffusion (to be
started in Phase 2)
 Interface conditions between matrix and fractures with
high permeability contrast (continuing into Phase 2)
 Dual-porosity vs. anomalous diffusion models
(continuing into Phase 2)
 Layered reservoir model (to be started in Phase 2)
 Drainage area and well spacing considerations (to be
started in Phase 2)
 Characterization and flow modeling (continuing into
Phase 2)
 Black-oil simulator incorporating bubble-point
suppression (complete)
 N-porosity simulation model (complete)
 DSMC and LB approaches for pore-scale modeling
 Pressure/Rate-transient model for gas flow toward
fractured horizontal wells with high variability of
viscosity-compressibility product (complete)
 Superposition time analysis for variable-rate gas
production under variable viscosity-compressibility
conditions (continuing into Phase 2)
 Well-interference model in fractured unconventional
reservoirs (continuing into Phase 2)
 Isochronal testing of wells in unconventional reservoirs
(continuing into Phase 2)
The major methodology of Phase 1 research was conceptual physical, analytical, and
mathematical. Phase 2 will also emphasize the experimental studies to verify the
new physical interpretations, constitutive relations, and flow models developed.
Experiments will also provide the data to be used in the models, construction and
verification of correlations, and the development of characterization guidelines. The
expansion of the nanofluidics laboratory established during Phase 1 will continue in
Phase 2 to improve its capabilities for more comprehensive investigations of the
fluid-phase behavior and flow in nanoporous environment. Core experiments may
also be considered depending on the progress and the needs of the selected projects.
A new experimental research area to be considered in Phase 2 is the steric
hindrance of hydrocarbon molecules in nanopore throats. This study will be a
continuation of the thermodynamic modeling performed in Phase 1, which has
indicated significant effect of filtration in nanoporous media, and should lead to new
projects to study EOR in unconventional reservoirs.
Further development of COZSim-UREP simulator by our research partner NITEC
will also continue during Phase 2. The new physical concepts and mechanisms
developed in various projects will be incorporated into COZSim-UREP to provide a
more comprehensive reservoir-modeling tool.
Another area of collaboration in numerical modeling is the use of the Direct
Simulation Monte Carlo (DSMC) approach. In this work, our research partner will be
Craft-Tech. We are planning to run DSMC tool developed by Craft-Tech to find out
whether DSMC can match the Lattice-Boltzmann (LB) results for the pore-scale
simulation of flow in nano-pores. Our expectation is to extend the simulations to
higher Knudsen numbers (Kn) for simple cubic (SC), body-centered cubic (BCC), and
face-centered cubic (FCC) geometries. These results will be used in the
interpretation of our nanofluidics experiments.
Analytical modeling of anomalous diffusion in fractured nanoporous media will also
be continued in Phase 2 and complemented by numerical modeling. One of the
major foci of this research will be the physical and practical interpretation of
process variables and phenomenological coefficients used in the fractional flux law
and anomalous diffusion equation. Comparison of anomalous diffusion models with
more conventional flow models, such as dual-porosity formulations, and
homogenization approaches, will also be performed.
Development of a practical superposition-time analysis method for gas flow with
pressure-dependent fluid properties will continue in Phase 2. This study will be
based on the new gas-flow solution for fractured wells with variable viscositycompressibility product developed in Phase 1. Similarly, the development of the
well interference model in globally and locally fractured tight porous media will
continue in to Phase 2 as this topic has relevance to the EOR considerations for
unconventional reservoirs. Also, the research on the use of isochronal-test ideas for
the evaluation of long-term tight-gas well performances from transient gas flow
data will continue in Phase 2.
Deliverables
The deliverables of the UREP Consortium are shown in Table 3. As noted earlier, the
delivery is subject to the availability of sufficient funding.
RESEARCH FOCUS
TABLE 3 – UREP Deliverables
Deliverables
PROJECT 1
Flow and Transport of
Hydrocarbon Fluids in NanoPorous Reservoirs
PROJECT 2
Fluid Transfer Between NanoPorous Matrix and Multi-Scale
Fractures
PROJECT 3
Production from Tight,
Fractured Formations in Close
Proximity of Source Rocks
(Liquid-Rich Reservoirs)
PROJECT 4
Simulation of Flow and
Transport in Fractured NanoPorous Reservoirs
PROJECT 5
Analysis and Prediction of
Well Performance in
Unconventional Reservoirs




Condensation-point suppression in pore proximity
Phase behavior results from nanofluidics experiments
Filtration results in nanopore throats
Analytical and numerical anomalous-diffusion models in
tight, fractured, unconventional reservoirs
 New models of fluid transfer from matrix to fractures
under different continuum conditions
 Comparisons of the new models with and existing
models
 Dual-porosity vs. anomalous diffusion models
 Layered reservoir model
 Drainage area and well spacing considerations
 Characterization and flow modeling guidelines
 Black-oil simulator incorporating condensation-point
enhancement
 N-porosity simulation model
 DSMC and LB models for pore-scale flow
 Superposition-time analysis for variable-rate gas
production under variable viscosity-compressibility
conditions
 Well-interference model in fractured unconventional
reservoirs
 Isochronal testing of wells in unconventional reservoirs
Advisory Board Meetings
There will be bi-annual AB meetings in the spring and the fall. The AB meetings for
Phase 2 of UREP have been tentatively scheduled on
Fall 2014 AB Meeting:
Spring 2015 AB Meeting:
Fall 2015 AB Meeting:
Spring 2016 AB Meeting:
Fall 2016 AB Meeting:
Nov. 13-14, 2014
May 1, 2015
Oct. 16, 2015
May 6, 2016
Oct. 27-28, 2016.
Fall 2014 and 2016 AB Meetings have been planned for two days because they will
serve as the closing meeting of the previous phase and the kick-off meeting of the
new phase.
Membership Fee
The membership fee is $45,000/year for the continuing members and $50,000/year
for the new members with two-year commitment. The payment schedule for the
membership fee is as follows:
Payment for Year 1: Due by December 1, 2014
Payment for Year 2: Due by December 1, 2015