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Consulting
| FracMan Group | Workshops
Compartmentalization Analysis
 The
FracMan technology group provides a range of services to support understanding
and engineering of compartmentalized and heterogeneously connected fractured
rocks:
- Identification and statistical analysis of fracture clusters, compartments,
and flow barriers,
- Analysis of flow dimension and connectivity variations at distance,
- Identification of flow pathways and their properties,
- Compartment volume analysis using convex hull and algorithm,
- Tributary drainage volume analysis based on identification of fracture clusters
connected to specific wells, and
- Calculation of the size and shape distributions of blocks defined by the
fracture network.
These analyses are carried out using FracWorks,
FraCluster, FlowDim,
PAWorks, and Flare.
Compartmentalization is a key issue for many oil and reservoirs. Within compartments,
pressure communication can be nearly instantaneous, while nearby wells in different
compartments may have very little communication. This situation can lead to
several undesired consequences, among them, unanticipated interference among
wells, reduced recovery efficiency, and increased production uncertainty. Estimating
the degree of compartmentalization is important at all stages of field development
in order to properly engineer the field and to provide realistic recovery estimates
and rates for financial decisions.
Compartmentalization may be due to several factors: fault offset of the producing
horizon; the existence of high permeability sub-vertical faults that form barriers
to lateral migration; the reduction in permeability of fractures due to mineralization;
and the natural geometrical clustering of joint and smaller fault networks when
matrix permeability is low. In terms of thermal recovery projects, there is
an additional type of compartmentalization that is dynamic. Injected steam loses
heat to the matrix and condenses. This condensation "front", which
may be less of a definable surface than it is a series of fingers reaching out
from the well along fracture paths, forms the steam "compartment".
Knowledge of the shape and extent of this compartment is crucial to optimizing
production. It is a combination of the natural geometrical compartmentalization
of the fracture networks, and the ability of the fractures in the networks to
exchange heat with the matrix. The geometry of the fracture networks places
constraints on the steam compartments; the steam compartments can never be bigger
than the networks themselves.
It is usually possible to identify large-scale fault-bounded reservoir compartments
from seismic or production histories. It is far more difficult to assess the
compartmentalization due to joint network geometry and connectivity, for which
seismic is of little use. Joint network compartmentalization is often suspected
when static and dynamic calculations of recoverable oil or gas do not agree,
and their is no evidence for fault-offset or others types of fault-related compartmentalization
in a fractured reservoir.
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