Changes

* Identify the major lithofacies, vertical sequences, and depositional environments from available core. Relate lithofacies, at the whole-core scale, to their mineralogical, textural, and pore level properties and to permeability, [[porosity]], fluid saturations, and capillarity as measured on core plugs. Establish consistent relationships between rock properties and petrophysical properties.

* Identify the major lithofacies, vertical sequences, and depositional environments from available core. Relate lithofacies, at the whole-core scale, to their mineralogical, textural, and pore level properties and to permeability, [[porosity]], fluid saturations, and capillarity as measured on core plugs. Establish consistent relationships between rock properties and petrophysical properties.

* Determine what lithofacies, or associations of lithofacies, are probable flow units based on petrophysical properties, changes in texture, cementation, [[fracture]] density, differences in sedimentary structures or bedding styles, and/or separations by prominent shales or other features that may bear on fluid distribution and flow.

* Determine what lithofacies, or associations of lithofacies, are probable flow units based on petrophysical properties, changes in texture, cementation, [[fracture]] density, differences in sedimentary structures or bedding styles, and/or separations by prominent shales or other features that may bear on fluid distribution and flow.

* Calibrate wireline log response to major rock types in as much detail as possible and with appropriate depth shifting of core to logs, in order to detect changes quantitatively in flow unit quality and to correlate major flow units to uncored wells. If cores are not available, cuttings, sidewall cores, patterns of textural change inferred from log signatures, cementation or shales detected on logs, downhole images of the borehole wall, microscanner logs, or other such information must be used in place of core (see [[Wireline methods]]).

* Calibrate wireline log response to major rock types in as much detail as possible and with appropriate depth shifting of core to logs, in order to detect changes quantitatively in flow unit quality and to correlate major flow units to uncored wells. If cores are not available, cuttings, sidewall cores, patterns of textural change inferred from log signatures, cementation or shales detected on logs, downhole images of the borehole wall, microscanner logs, or other such information must be used in place of core.

* Establish the three-dimensional distribution of flow units by correlation of calibrated wireline logs. Knowledge of environments of deposition of the reservoir sequence is important to interpreting the style of correlation to be used and the expected patterns of external and internal geometry of any flow unit (see [[Lithofacies and environmental analysis of clastic depositional systems]]). During correlation, the flow unit zonation established in individual cored wells may change somewhat. Tying correlation horizons around a loop is critical because individual correlation sections alone can be deceptive.

* Establish the three-dimensional distribution of flow units by correlation of calibrated wireline logs. Knowledge of environments of deposition of the reservoir sequence is important to interpreting the style of correlation to be used and the expected patterns of external and internal geometry of any flow unit (see [[Lithofacies and environmental analysis of clastic depositional systems]]). During correlation, the flow unit zonation established in individual cored wells may change somewhat. Tying correlation horizons around a loop is critical because individual correlation sections alone can be deceptive.

* Test the validity of flow units established by consideration of production logs (see [[Production engineering methods]]), flow tests of small intervals, oil and water geochemistry (see [[Laboratory methods]]), repeat formation tester (RFT) surveys (see [[Wireline methods]]), injectivity logs, tracer surveys, and any available data on patterns of production through time. Modify the flow unit definitions as needed to accommodate the physical measurements of flow, if a rationale can be found for the differences.

* Test the validity of flow units established by consideration of production logs, flow tests of small intervals, oil and water geochemistry, [[Wireline formation testers|repeat formation tester (RFT)]] surveys, injectivity logs, tracer surveys, and any available data on patterns of production through time. Modify the flow unit definitions as needed to accommodate the physical measurements of flow, if a rationale can be found for the differences.

The distribution of petrophysical properties such as porosity and permeability can be mapped within flow units using well control only or by applying geostatistical procedures to create stochastic realizations of these distributions “conditioned” on the well data (see [[Geological methods]]). Geostatistical techniques that have a strong stochastic component are consistent with, and complementary to, the flow unit concept, which is itself mostly deterministic.

The distribution of petrophysical properties such as porosity and permeability can be mapped within flow units using well control only or by applying geostatistical procedures to create stochastic realizations of these distributions “conditioned” on the well data. Geostatistical techniques that have a strong stochastic component are consistent with, and complementary to, the flow unit concept, which is itself mostly deterministic.

==Examples of application of flow units==

==Examples of application of flow units==