Changes

''Type 4''—Impart no positive [[reservoir quality]] but create strong reservoir anisotropy and inhomogeneity<ref name=pt06r95>Nelson, R. A., 1985, Geologic analysis of naturally fractured reservoirs—Contributions in Petroleum Geology and Engineering #1: Houston, TX, Gulf Publishing Company, 320 p.</ref>

''Type 4''—Impart no positive [[reservoir quality]] but create strong reservoir anisotropy and inhomogeneity<ref name=pt06r95>Nelson, R. A., 1985, Geologic analysis of naturally fractured reservoirs—Contributions in Petroleum Geology and Engineering #1: Houston, TX, Gulf Publishing Company, 320 p.</ref>

}}

}}

Anticipated exploration and development problems associated with these four reservoir types are summarized in Table 1 and Table 2.

Anticipated exploration and development problems associated with these four reservoir types are summarized in Table 1 and Table 2.

! Reservoir Formation Problem || Approach

! Reservoir Formation Problem || Approach

|-

|-

| Reservoir performance is controlled by sedimentary facies, lithology and/or geometry || Determine sedimentary characteristics and origin of facies through [[core description]] and construct predictive models for lateral variability and heterogeneity of reservoir units

| Reservoir performance is controlled by sedimentary facies, lithology and/or geometry || Determine sedimentary characteristics and origin of facies through [[core description]] and construct predictive models for [[lateral]] variability and heterogeneity of reservoir units

|-

|-

| Reservoir performance and formation permeabilities are negatively impacted by presence of [http://dictionary.reference.com/browse/detrital detrital] or [http://dictionary.reference.com/browse/authigenic authigenic] clays (very common) || Identify and map reservoir facies with the least detrital clay content; avoid treatment of formation by [[Stimulation#Acidizing|acidization]] or injection of any fluids; use [[Drilling_fluid#Oil-based_muds|oil-based muds]]; enhance recovery through [[Stimulation#Hydraulic_fracturing|artificial fracturing]] of the formation<ref name=pt06r93>Moslow, T. F., Tillman, R. W., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0250/0271.htm Sedimentary facies and reservoir characteristics of Frontier Formation sandstones, southwestern Wyoming], in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 271–295.</ref>

| Reservoir performance and formation permeabilities are negatively impacted by presence of [http://dictionary.reference.com/browse/detrital detrital] or [http://dictionary.reference.com/browse/authigenic authigenic] clays (very common) || Identify and map reservoir facies with the least detrital clay content; avoid treatment of formation by [[Stimulation#Acidizing|acidization]] or injection of any fluids; use [[Drilling_fluid#Oil-based_muds|oil-based muds]]; enhance recovery through [[Stimulation#Hydraulic_fracturing|artificial fracturing]] of the formation<ref name=pt06r93>Moslow, T. F., and R. W. Tillman, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0250/0271.htm Sedimentary facies and reservoir characteristics of Frontier Formation sandstones, southwestern Wyoming], in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 271–295.</ref>

|-

|-

| Reservoir performance is dictated by origin and distribution of natural fractures || Evaluate the relationship between [[fracture]] occurrence and lithology<ref name=pt06r100>Pitman, J. K., Sprunt, E. S., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0200/0221.htm Origin and distribution of fractures in Lower Tertiary and Upper Cretaceous rocks, Piceance basin, Colorado, and their relation to the occurrence of hydrocarbons] in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 221–234.</ref>

| Reservoir performance is dictated by origin and distribution of natural fractures || Evaluate the relationship between [[fracture]] occurrence and lithology<ref name=pt06r100>Pitman, J. K., and E. S. Sprunt, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0200/0221.htm Origin and distribution of fractures in Lower Tertiary and Upper Cretaceous rocks, Piceance basin, Colorado, and their relation to the occurrence of hydrocarbons] in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 221–234.</ref>

|-

|-

| Fracture mineralization impacts reservoir performance. || Determine the nature, origin, and timing of mineralization through petrographical and [[Wikipedia:Isotope geochemistry|stable isotope techniques]]<ref name=pt06r100 />

| Fracture mineralization impacts reservoir performance. || Determine the nature, origin, and timing of mineralization through petrographical and [[Wikipedia:Isotope geochemistry|stable isotope techniques]]<ref name=pt06r100 />

| [[Porosity]] and [[permeability]] trends are controlled by clay [[diagenesis]] or [[secondary cements]] || Determine the petrological and mineralogical history of reservoir facies; identify and map “diagenetic facies” relative to sedimentary facies

| [[Porosity]] and [[permeability]] trends are controlled by clay [[diagenesis]] or [[secondary cements]] || Determine the petrological and mineralogical history of reservoir facies; identify and map “diagenetic facies” relative to sedimentary facies

|-

|-

| Reservoir gas [[accumulation]]s lack a [[floored]] [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contact] || Map structural, isothermal, and pressure gradient contours that are likely coincident with boundaries of the gas envelope<ref name=pt06r113>Rose, P. R., Everett, J. R., Merin, I. A., 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0100/0111.htm Potential basin-centered gas accumulation in Cretaceous Trinidad Sandstone, Raton Basin, Colorado] in Spencer, C. W., Mast, R. F., eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 111–128.</ref>

| Reservoir gas [[accumulation]]s lack a [[floored]] [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contact] || Map structural, isothermal, and pressure gradient contours that are likely coincident with boundaries of the gas envelope<ref name=pt06r113>Rose, P. R., J. R. Everett, and I. A. Merin, 1986, [http://archives.datapages.com/data/specpubs/resmi1/data/a066/a066/0001/0100/0111.htm Potential basin-centered gas accumulation in Cretaceous Trinidad Sandstone, Raton Basin, Colorado] in C. W. Spencer, and R. F. Mast, eds., Geology of Tight Gas Reservoirs: AAPG Studies in Geology Series 24, p. 111–128.</ref>

|-

|-

| [[Overpressure causes|Overpressured]] formation or reservoir (occurs frequently due to common distribution of [[Evaluating tight gas reservoirs|tight gas]] with basin center locations and excessive [[overburden]]) || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery

| [[Overpressure causes|Overpressured]] formation or reservoir (occurs frequently due to common distribution of [[Evaluating tight gas reservoirs|tight gas]] with basin center locations and excessive overburden) || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery

|-

|-

| [[Underpressure causes|Underpressured]] formation or reservoir due to stripping (erosion) of overburden || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery

| [[Underpressure causes|Underpressured]] formation or reservoir due to stripping (erosion) of overburden || Requires appropriate exploration strategies or reservoir engineering approach to gas recovery

| Best to have fractures of one orientation than multiple intersecting trends

| Best to have fractures of one orientation than multiple intersecting trends

|}

|}

==Evaluation==

==Evaluation==

When evaluating a [[fracture]]d reservoir, the analyst must follow these steps:<ref name=pt06r95 />

When evaluating a [[fracture]]d reservoir, the analyst must follow these steps:<ref name=pt06r95 />

* Determine the origin of the fracture system found or the type of fracture system that is being explored for based on geometric characteristics of the fractures, their distribution in three dimensions, and empirical models of fracture system genesis.<ref name=pt06r135>Stearns, D. W., Friedman, M. 1972, [http://archives.datapages.com/data/specpubs/fieldst4/data/a010/a010/0001/0050/0082.htm Reservoirs in fractured rock] in Stearns, D. W., and Friendman, N., Stratigraphic Oil and Gas Fields--Classification, Exploration Methods and Case Histories: AAPG Memoir 16, p. 82–100.</ref>

* Determine the origin of the fracture system found or the type of fracture system that is being explored for based on geometric characteristics of the fractures, their distribution in three dimensions, and empirical models of fracture system genesis.<ref name=pt06r135>Stearns, D. W., and M. Friedman, 1972, [http://archives.datapages.com/data/specpubs/fieldst4/data/a010/a010/0001/0050/0082.htm Reservoirs in fractured rock] in D. W. Stearns, and N. Friendman, Stratigraphic Oil and Gas Fields--Classification, Exploration Methods and Case Histories: AAPG Memoir 16, p. 82–100.</ref>

* Determine the reservoir properties of both the rock [http://www.britannica.com/EBchecked/topic/369508/matrix matrix] housing the fractures and the fracture system.<ref name=pt06r145>van Golf-Racht, T. D., 1982, Fundamentals of fractured reservoir engineering—Developments in Petroleum Science No. 12: Amsterdam, Elsevier Scientific Publishing Co., 710 p.</ref>

* Determine the reservoir properties of both the rock [http://www.britannica.com/EBchecked/topic/369508/matrix matrix] housing the fractures and the fracture system.<ref name=pt06r145>van Golf-Racht, T. D., 1982, Fundamentals of fractured reservoir engineering—Developments in Petroleum Science No. 12: Amsterdam, Elsevier Scientific Publishing Co., 710 p.</ref>

* Determine the degree of [[Fundamentals of fluid flow|fluid flow]] interaction or crossflow in either a qualitative or quantitative manner.

* Determine the degree of [[Fundamentals of fluid flow|fluid flow]] interaction or crossflow in either a qualitative or quantitative manner.

[[file:evaluating-fractured-reservoirs_fig2.png|300px|thumb|{{figure number|2}}Schematic of typical features to measure and record in core analysis. © van Golf-Racht, 1982; courtesy of Elsevier. Typical recording format from <ref name=pt06r108>Reiss, L. H., 1980, The reservoir engineering aspects of fractured formations: Houston, TX, Gulf Publishing Company, 108 p.</ref>; courtesy of Gulf Publishing Co.]]

[[file:evaluating-fractured-reservoirs_fig2.png|300px|thumb|{{figure number|2}}Schematic of typical features to measure and record in core analysis. © van Golf-Racht, 1982; courtesy of Elsevier. Typical recording format from <ref name=pt06r108>Reiss, L. H., 1980, The reservoir engineering aspects of fractured formations: Houston, TX, Gulf Publishing Company, 108 p.</ref>; courtesy of Gulf Publishing Co.]]

The following procedures have proven useful in [[Fracture analysis|fracture analyses]] of core (after <ref name=pt06r95 />):

The following procedures have proven useful in [[Fracture analysis|fracture analyses]] of core:<ref name=pt06r95 />

# Lay out all of the core from a given well for observation. Fit the core together and note continuous segments (see [[Core handling]]).

# Lay out all of the core from a given well for observation. Fit the core together and note continuous segments (see [[Core handling]]).

# Have the core analyses ([[porosity]] and [[permeability]]) data in hand while observing the core to determine the relative effect of the features observed. Obtain three-dimensional whole-core analyses, if possible, when the fractures or other anisotropic features are predicted to be important.

# Have the core analyses ([[porosity]] and [[permeability]]) data in hand while observing the core to determine the relative effect of the features observed. Obtain three-dimensional whole-core analyses, if possible, when the fractures or other anisotropic features are predicted to be important.

# Create the fracture stratigraphy (involves steps 5 through 16).

# Create the fracture stratigraphy (involves steps 5 through 16).

# Construct a core deformation strip log at a relevant scale that includes the positioning of major lithology and formation breaks, lost core and noncored intervals, [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=oil-water+contact oil-water]  or [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contacts]] (if available), fractures, and [http://www.merriam-webster.com/dictionary/stylolite stylolites]. Hairline fractures in the core are often difficult to see. These can be enhanced by painting the core with a volatile liquid and observing the drying pattern. Overlooked fractures may “jump out” at the observer by persistence of wetting along hairline fractures reaching the core surface. Additional characterization of hairline or larger fractures internal to the core can be accomplished by core [http://www.thefreedictionary.com/radiograph X-radiographs] or core computer [http://www.merriam-webster.com/medical/tomography tomography] scans.

# Construct a core [[deformation]] strip log at a relevant scale that includes the positioning of major lithology and formation breaks, lost core and noncored intervals, [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=oil-water+contact oil-water]  or [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=gas-water+contact gas-water contacts]] (if available), fractures, and [http://www.merriam-webster.com/dictionary/stylolite stylolites]. Hairline fractures in the core are often difficult to see. These can be enhanced by painting the core with a volatile liquid and observing the drying pattern. Overlooked fractures may “jump out” at the observer by persistence of wetting along hairline fractures reaching the core surface. Additional characterization of hairline or larger fractures internal to the core can be accomplished by core [http://www.thefreedictionary.com/radiograph X-radiographs] or core computer [http://www.merriam-webster.com/medical/tomography tomography] scans.

# Record the fracture distribution with depth ([[:file:evaluating-fractured-reservoirs_fig2.png|Figure 2]]). (Recording of this and all following data could be done in a tabular format compatible with computer entry to facilitate output compatible with other strip and well logs.)

# Record the fracture distribution with depth ([[:file:evaluating-fractured-reservoirs_fig2.png|Figure 2]]). (Recording of this and all following data could be done in a tabular format compatible with computer entry to facilitate output compatible with other strip and well logs.)

# Relate fracture distribution to rock type.

# Relate fracture distribution to rock type.

# Record the [[dip]] of fractures either real or apparent.

# Record the [[dip]] of fractures either real or apparent.

# Back up core observations with appropriate logs from the same zones as core from the well for effective extrapolation to uncored wells (see [[Formation evaluation of naturally fractured reservoirs]]). Record the [[strike]] of features if the core is oriented core or if it is locally oriented either mechanically or by oriented logs such as the Borehole Televiewer, Formation MicroScanner, or high-resolution dipmeter.<ref name=pt06r101>Plumb, R. A., Luthi, S. M., 1986, Application of borehole images to geologic modeling of an eolian reservoir: 61st Annual Technical Conference of the Society of Petroleum Engineers, New Orleans, LA, Oct. 5–8, SPE 15487, 11. p.</ref> (For more on these methods, see [[Core orientation]], [[Borehole imaging devices]], and [[Dipmeter]].)

# Back up core observations with appropriate logs from the same zones as core from the well for effective extrapolation to uncored wells (see [[Formation evaluation of naturally fractured reservoirs]]). Record the [[strike]] of features if the core is oriented core or if it is locally oriented either mechanically or by oriented logs such as the Borehole Televiewer, Formation MicroScanner, or high-resolution dipmeter.<ref name=pt06r101>Plumb, R. A., and S. M. Luthi, 1986, Application of borehole images to geologic modeling of an eolian reservoir: 61st Annual Technical Conference of the Society of Petroleum Engineers, New Orleans, LA, Oct. 5–8, SPE 15487, 11. p.</ref> (For more on these methods, see [[Core orientation]], [[Borehole imaging devices]], and [[Dipmeter]].)

# Look for intersection angles of fractures as expressed on the outside surface of the core or on the ends of the samples and record the true or apparent angles ([[:file:evaluating-fractured-reservoirs_fig2.png|Figure 2]]).

# Look for intersection angles of fractures as expressed on the outside surface of the core or on the ends of the samples and record the true or apparent angles ([[:file:evaluating-fractured-reservoirs_fig2.png|Figure 2]]).

# Determine which of the fractures in the core are natural or induced.<ref name=pt06r69>Kulander, B. R., Dean, S. L., 1985, Hackle plume geometry and joint propagation dynamics, in Stephansson, O. ed., Fundamentals of Rock Joints: Proceedings of the International Symposium, Bjorkliden, Sept. 15–20, p. 85–94.</ref>

# Determine which of the fractures in the core are natural or induced.<ref name=pt06r69>Kulander, B. R., and S. L. Dean, 1985, Hackle plume geometry and joint propagation dynamics, in O. Stephansson, ed., Fundamentals of Rock Joints: Proceedings of the International Symposium, Bjorkliden, Sept. 15–20, p. 85–94.</ref>

# Describe stylolite distribution (position, rock type, and postulated σ₁.<ref name=pt06r95 /><ref name=pt06r145 />

# Describe stylolite distribution (position, rock type, and postulated σ₁.<ref name=pt06r95 /><ref name=pt06r145 />

# Determine fracture plane morphology, paying particular attention to any partial mineralization along the fracture planes that might act as a natural [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=proppant proppant] during depletion.<ref name=pt06r95 /> If present, determine its mineralogy and predicted relative compressive strength.

# Determine fracture plane morphology, paying particular attention to any partial mineralization along the fracture planes that might act as a natural [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=proppant proppant] during depletion.<ref name=pt06r95 /> If present, determine its [[mineralogy]] and predicted relative compressive strength.

# Measure the relative size or height of the fractures, paying particular attention to any rock features that tend to control the vertical extent of the fractures, such as lithology breaks, bedding planes, stylolites, or [[Unconformity|unconformities]].

# Measure the relative size or height of the fractures, paying particular attention to any rock features that tend to control the vertical extent of the fractures, such as lithology breaks, bedding planes, stylolites, or [[Unconformity|unconformities]].

# Observe the width and width variation of the fractures. Measurements of width could be made with a scale, [http://www.merriam-webster.com/dictionary/micrometer micrometer], or caliper or by impregnation with epoxy or plastic for either thin section measurement of epoxy width or dissolution of matrix leaving the width at the depth approximated.<ref name=pt06r95 />

# Observe the width and width variation of the fractures. Measurements of width could be made with a scale, [http://www.merriam-webster.com/dictionary/micrometer micrometer], or caliper or by impregnation with epoxy or plastic for either thin section measurement of epoxy width or dissolution of matrix leaving the width at the depth approximated.<ref name=pt06r95 />

# Estimate or measure fracture spacing and its variability with depth.<ref name=pt06r94>Narr, W., Lerche, I. 1984, [http://archives.datapages.com/data/bulletns/1984-85/data/pg/0068/0005/0600/0637.htm A method for estimating subsurface fracture density in core]: AAPG Bulletin, v. 68, p. 637–648.</ref><ref name=pt06r96>Nolen-Hoeksema, R. C., Howard, J. H., 1987, [http://archives.datapages.com/data/bulletns/1986-87/data/pg/0071/0008/0950/0958.htm Estimating drilling direction for optimum production in a fractured reservoir]: AAPG Bulletin, v. 71, p. 958–966.</ref>

# Estimate or measure fracture spacing and its variability with depth.<ref name=pt06r94>Narr, W., and I. Lerche, 1984, [http://archives.datapages.com/data/bulletns/1984-85/data/pg/0068/0005/0600/0637.htm A method for estimating subsurface fracture density in core]: AAPG Bulletin, v. 68, p. 637–648.</ref><ref name=pt06r96>Nolen-Hoeksema, R. C., and J. H. Howard, 1987, [http://archives.datapages.com/data/bulletns/1986-87/data/pg/0071/0008/0950/0958.htm Estimating drilling direction for optimum production in a fractured reservoir]: AAPG Bulletin, v. 71, p. 958–966.</ref>

# Determine principal [[Wikipedia:Stress (mechanics)|stress]] directions and the origin and continuity of the fracture system(s).<ref name=pt06r135 /><ref name=pt06r95 />

# Determine principal [[Wikipedia:Stress (mechanics)|stress]] directions and the origin and continuity of the fracture system(s).<ref name=pt06r135 /><ref name=pt06r95 />

# Determine the relative timing of [[deformation]]al events from cross-cutting relationships or [[paragenetic sequence]].<ref name=pt06r77>Lindquist, S. J., 1983, Nugget Formation reservoir characteristics affecting production the Overthrust Belt of southwestern Wyoming: Journal of Petroleum Technology, July, p. 1355–1365.</ref>

# Determine the relative timing of [[deformation]]al events from cross-cutting relationships or [[paragenetic sequence]].<ref name=pt06r77>Lindquist, S. J., 1983, Nugget Formation reservoir characteristics affecting production the Overthrust Belt of southwestern Wyoming: Journal of Petroleum Technology, July, p. 1355–1365.</ref>

==Outcrop analysis==

==Outcrop analysis==

When collecting [[fracture]] data from outcrops, one should look for rocks similar to the [[reservoir]] rocks of interest on similar outcropping structures. Look at more of the rock section than just the prospective reservoir rock, including potential sealing beds, and pay attention to relative fracture intensity between layered units.

When collecting [[fracture]] data from [http://www.merriam-webster.com/dictionary/outcrop outcrops], one should look for rocks similar to the [[reservoir]] rocks of interest on similar outcropping structures. Look at more of the rock section than just the prospective reservoir rock, including potential sealing beds, and pay attention to relative fracture intensity between layered units.

* Select outcrop areas having representative fracture patterns for specific structural positions. Record [[strik]]e and [[dip]] data, or at least strike data. Additional sites can be chosen for one unit at different positions within the structure.

* Select outcrop areas having representative fracture patterns for specific structural positions. Record [[strik]]e and [[dip]] data, or at least strike data. Additional sites can be chosen for one unit at different positions within the structure.

# '''Document fracture presence'''

# '''Document fracture presence'''

#* Logs<ref name=pt06r1 />

#* [[Basic open hole tools|Logs]]<ref name=pt06r1 />

#* Cores<ref name=pt06r95 />

#* [[Overview of routine core analysis|Cores]]<ref name=pt06r95 />

#* Anomalous flow rates<ref name=pt06r1 />

#* Anomalous flow rates<ref name=pt06r1 />

# '''Determine if structure is present'''

# '''Determine if structure is present'''

#* Seismic, gravity, magnetics

#* [[Seismic data|Seismic]], [[Gravity basics|gravity]], [[magnetics]]

#* Structure maps

#* [[Subsurface_maps#Structure|Structure maps]]

#* Dipmeters<ref name=pt06r101 />

#* [[Dipmeter]]s<ref name=pt06r101 />

# '''Determine lithological control of fracture distribution'''

# '''Determine lithological control of fracture distribution'''

#* Logs<ref name=pt06r1 />

#* Logs<ref name=pt06r1 />

#* Cores and fracture stratigraphy<ref name=pt06r95 />

#* Cores and fracture stratigraphy<ref name=pt06r95 />

#* Logs and flow tests or DSTs<ref name=pt06r1 /><ref name=pt06r145 />

#* Logs and [[Production_logging#Quantitative_flow_evaluation|flow tests]] or [[Drill stem testing|DSTs]]<ref name=pt06r1 /><ref name=pt06r145 />

# '''Document fracture systems geometry'''

# '''Document fracture systems geometry'''

#* Borehole Televiewer or Formation MicroScanner<ref name=pt06r101 />

#* [[Borehole imaging devices|Borehole Televiewer or Formation MicroScanner]]<ref name=pt06r101 />

#* Cores<ref name=pt06r95 />

#* Cores<ref name=pt06r95 />

#* Predictions (including relevant outcrops)<ref name=pt06r135 /><ref name=pt06r95 />

#* Predictions (including relevant outcrops)<ref name=pt06r135 /><ref name=pt06r95 />

#* Extrapolation using fracture type and observations

#* Extrapolation using fracture type and observations

# '''Estimate fracture spacing and spacing variability'''

# '''Estimate fracture spacing and spacing variability'''

#* Cores (<ref name=pt06r95 />; Narr and Lerche, 1984)

#* Cores<ref name=pt06r95 /><ref name=pt06r94 />

#* Borehole Televiewer (Plumb and Luthi, 1986)

#* Borehole Televiewer<ref name=pt06r101 />

#* Predictions (including relevant outcrops) (<ref name=pt06r95 />; La Pointe and Hudson, 1985)

#* Predictions (including relevant outcrops)<ref name=pt06r95 /><ref name=LaPointe>La Pointe, P. R., and J. A. Hudson, 1985, Characterization and interpretation of rock mass joint patterns: Geological Society of America Special Paper 199, 37 p.</ref>

# '''Estimate fracture width'''

# '''Estimate fracture width'''

#* Laboratory data

#* Laboratory data

#* Flow test data

#* Flow test data

#* Thin sections

#* [[Thin section analysis|Thin sections]]

#* Impregnation and dissolution

#* Impregnation and dissolution

# '''Estimate reservoir properties at depth'''

# '''Estimate reservoir properties at depth'''

#* Early exploration evaluation

#* Early exploration evaluation

#* Estimation of economic potential

#* Estimation of economic potential

#* Recovery planning and reservoir modeling

#* Recovery planning and [[Reservoir modeling for simulation purposes|reservoir modeling]]

==See also==

==See also==

[[Category:Geological methods]]

[[Category:Geological methods]]