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The single-well chemical tracer (SWCT) test is an in-situ method for measuring fluid saturations in reservoirs. Most often, [[Residual oil evaluation using single well chemical tracer test|residual oil saturation]] is measured; less frequently, [[Connate water saturation evaluation|connate water saturation]] (''S''<sub>''wc''</sub>) is the objective. Either saturation is measured where one phase effectively is stationary in the pore space (i.e., is at residual saturation) and the other phase can flow to the wellbore. Recently, the SWCT method has been extended to measure oil/water fractional flow at measured fluid saturations in situations in which both oil and water phases are mobile.  
The single-well chemical tracer (SWCT) test is an in-situ method for measuring fluid saturations in reservoirs. Most often, [[Residual_oil_evaluation_using_single_well_chemical_tracer_test|residual oil saturation]] is measured; less frequently, [[Connate_water_saturation_evaluation|connate water saturation]] (''S''<sub>''wc''</sub>) is the objective. Either saturation is measured where one phase effectively is stationary in the pore space (i.e., is at residual saturation) and the other phase can flow to the wellbore. Recently, the SWCT method has been extended to measure oil/water fractional flow at measured fluid saturations in situations in which both oil and water phases are mobile.


==Primary use==
== Primary use ==
The SWCT test is used primarily to quantify the target oil saturation before initiating improved oil recovery (IOR) operations, to measure the effectiveness of IOR agents in a single well pilot and to assess a field for bypassed oil targets. Secondarily, it is used to measure ''S''<sub>''wc''</sub> accurately for better evaluation of original [[Resources and reserves models#Variations of the volumetric formula|oil in place (OOIP)]]. Fractional flow measurement provides realistic input for simulator models used to calculate expected [[Waterflooding|waterflood]] performance.  
 
The SWCT test is used primarily to quantify the target oil saturation before initiating improved oil recovery (IOR) operations, to measure the effectiveness of IOR agents in a single well pilot and to assess a field for bypassed oil targets. Secondarily, it is used to measure ''S''<sub>''wc''</sub> accurately for better evaluation of original [[Resources_and_reserves_models#Variations_of_the_volumetric_formula|oil in place (OOIP)]]. Fractional flow measurement provides realistic input for simulator models used to calculate expected [[Waterflooding|waterflood]] performance.


== History ==
== History ==
The first SWCT test for residual oil saturation (''S''<sub>''or''</sub>) was run in the East Texas Field in 1968.<ref name="r1" /> Patent rights were issued in 1971.<ref name="r2" /> Since then, numerous oil companies have used the SWCT method.<ref name="r3" /><ref name="r4" /><ref name="r5" /><ref name="r6" /><ref name="r7" /> More than 400 SWCT tests have been carried out, mainly to measure ''S''<sub>''or''</sub> after [[Waterflooding|waterflooding]].


The SWCT method has gained considerable recognition over the past few years because of increasing interest in the quantitative measurement of ''S''<sub>''or''</sub>. Some experts<ref name="r8" /><ref name="r9" /> consider the SWCT test to be the method of choice because of its demonstrated accuracy and reasonable cost.  
The first SWCT test for residual oil saturation (''S''<sub>''or''</sub>) was run in the East Texas Field in 1968.<ref name="r1">_</ref> Patent rights were issued in 1971.<ref name="r2">_</ref> Since then, numerous oil companies have used the SWCT method.<ref name="r3">_</ref><ref name="r4">_</ref><ref name="r5">_</ref><ref name="r6">_</ref><ref name="r7">_</ref> More than 400 SWCT tests have been carried out, mainly to measure ''S''<sub>''or''</sub> after [[Waterflooding|waterflooding]].
 
The SWCT method has gained considerable recognition over the past few years because of increasing interest in the quantitative measurement of ''S''<sub>''or''</sub>. Some experts<ref name="r8">_</ref><ref name="r9">_</ref> consider the SWCT test to be the method of choice because of its demonstrated accuracy and reasonable cost.


== Measuring residual oil saturation ==
== Measuring residual oil saturation ==
Accurate ''S''<sub>''or''</sub> measurement is important because of a combination of basic problems in oil recovery. The industry still produces less than half the oil in the reservoirs discovered, and nearly all that oil is produced using traditional primary and secondary recovery methods.<ref name="r10" /> Furthermore, as the cost of finding new reserves continues to increase, especially in the US, the oil remaining in old fields becomes a significant economic target for infill drilling and IOR projects.


In every target field, the quantity and location of the remaining oil must be determined. '''Fig. 1a''' illustrates the principle of material balance, as applied to an oil reservoir. The entire area of the graph represents the reservoir pore volume (''V''<sub>''p''</sub>), which is known with varying degrees of uncertainty. The produced oil, corrected back to reservoir conditions, is the middle area; its accuracy, however, depends on how thoroughly production records have been kept.  
Accurate ''S''<sub>''or''</sub> measurement is important because of a combination of basic problems in oil recovery. The industry still produces less than half the oil in the reservoirs discovered, and nearly all that oil is produced using traditional primary and secondary recovery methods.<ref name="r10">_</ref> Furthermore, as the cost of finding new reserves continues to increase, especially in the US, the oil remaining in old fields becomes a significant economic target for infill drilling and IOR projects.
 
In every target field, the quantity and location of the remaining oil must be determined. '''Fig. 1a''' illustrates the principle of material balance, as applied to an oil reservoir. The entire area of the graph represents the reservoir pore volume (''V''<sub>''p''</sub>), which is known with varying degrees of uncertainty. The produced oil, corrected back to reservoir conditions, is the middle area; its accuracy, however, depends on how thoroughly production records have been kept.


The uppermost area is the [[Glossary:Connate water|connate water]], which is known only as well as available methods and coverage of measurements allow. The lowermost area, the remaining oil, can be expressed as an average saturation of oil [[File:Vol5 page 0616 inline 001.png]], if we accept the total pore volume ''V''<sub>''p''</sub>, produced oil, and ''S''<sub>''wc''</sub> values as being accurate.  
The uppermost area is the [[Glossary:Connate_water|connate water]], which is known only as well as available methods and coverage of measurements allow. The lowermost area, the remaining oil, can be expressed as an average saturation of oil [[File:Vol5 page 0616 inline 001.png|RTENOTITLE]], if we accept the total pore volume ''V''<sub>''p''</sub>, produced oil, and ''S''<sub>''wc''</sub> values as being accurate.


If a given field has been waterflooded, the fraction of the OOIP displaced by the water is a critical parameter. Testing for ''S''<sub>''or''</sub> in watered-out wells in the field can determine the maximum waterflood displacement efficiency. A significant difference between the material-balance ''S''<sub>''o''</sub> and the measured ''S''<sub>''or''</sub> would indicate the presence of bypassed oil. This would signify that parts of the reservoir had not been contacted by injected water, or had not received sufficient water throughput to reach ''S''<sub>''or''</sub>. This concept is shown in '''Fig. 1b'''.  
If a given field has been waterflooded, the fraction of the OOIP displaced by the water is a critical parameter. Testing for ''S''<sub>''or''</sub> in watered-out wells in the field can determine the maximum waterflood displacement efficiency. A significant difference between the material-balance ''S''<sub>''o''</sub> and the measured ''S''<sub>''or''</sub> would indicate the presence of bypassed oil. This would signify that parts of the reservoir had not been contacted by injected water, or had not received sufficient water throughput to reach ''S''<sub>''or''</sub>. This concept is shown in '''Fig. 1b'''.


<gallery widths="300px" heights="200px">
<gallery widths="300px" heights="200px">
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</gallery>
</gallery>


A reliable in-situ measurement of ''S''<sub>''or''</sub> simultaneously defines the target for enhanced oil recovery (EOR) and allows estimation of the potential bypassed (mobile) oil in the field. This moveable oil is the target for infill drilling and/or flood sweep efficiency improvements.  
A reliable in-situ measurement of ''S''<sub>''or''</sub> simultaneously defines the target for enhanced oil recovery (EOR) and allows estimation of the potential bypassed (mobile) oil in the field. This moveable oil is the target for infill drilling and/or flood sweep efficiency improvements.


Because ''S''<sub>''or''</sub> varies greatly with formation type, oil/water properties, and other variables that are not completely understood (e.g., wettability changes caused by water flood practices), ''S''<sub>''or''</sub> measurements range from < 10% to > 45%. There is no reliable way to predict ''S''<sub>''or''</sub> with acceptable accuracy for most reservoirs. Furthermore, measuring residual oil is not easy. Laboratory corefloods performed at other than native state wettability are unreliable.<ref name="r11" />  
Because ''S''<sub>''or''</sub> varies greatly with formation type, oil/water properties, and other variables that are not completely understood (e.g., wettability changes caused by water flood practices), ''S''<sub>''or''</sub> measurements range from &lt; 10% to &gt; 45%. There is no reliable way to predict ''S''<sub>''or''</sub> with acceptable accuracy for most reservoirs. Furthermore, measuring residual oil is not easy. Laboratory corefloods performed at other than native state wettability are unreliable.<ref name="r11">_</ref>


Well logs can give vertical profiles of ''S''<sub>''or''</sub> under optimal conditions, but their results are not absolute. Logs of all types require calibration by an independent method, which gives either a quantitative ''S''<sub>''o''</sub> at some point or an average ''S''<sub>''o''</sub> over some layer. Pressure cores or sponge cores can provide this calibration, but require a new well and are subject to saturation disturbances caused by mud filtrate invasion.  
Well logs can give vertical profiles of ''S''<sub>''or''</sub> under optimal conditions, but their results are not absolute. Logs of all types require calibration by an independent method, which gives either a quantitative ''S''<sub>''o''</sub> at some point or an average ''S''<sub>''o''</sub> over some layer. Pressure cores or sponge cores can provide this calibration, but require a new well and are subject to saturation disturbances caused by mud filtrate invasion.


An advantage of the SWCT method is that it pushes tracers beyond damaged regions near the wellbore and into layers that are known to be at residual oil conditions. The tracers go where water is contacting the residual oil, as shown in '''Fig. 1b'''.  
An advantage of the SWCT method is that it pushes tracers beyond damaged regions near the wellbore and into layers that are known to be at residual oil conditions. The tracers go where water is contacting the residual oil, as shown in '''Fig. 1b'''.


In an SWCT test, the formation volume sampled is large enough to be representative. A typical test quickly investigates hundreds of barrels of pore space in an existing watered-out well. The tracer-bearing fluids are produced back into the well without disturbing the formation, allowing further testing.
In an SWCT test, the formation volume sampled is large enough to be representative. A typical test quickly investigates hundreds of barrels of pore space in an existing watered-out well. The tracer-bearing fluids are produced back into the well without disturbing the formation, allowing further testing.


== Measuring connate water saturation ==
== Measuring connate water saturation ==
[[Connate water saturation evaluation|Connate water saturation]] is more variable (and less predictable) than ''S''<sub>''or''</sub>, with ''S''<sub>''wc''</sub> measurements ranging from > 50% in certain rock types to < 5% in unusual reservoir situations. Large variations within the producing intervals of major reservoirs are well documented.<ref name="r9" />


As '''Figs. 1a''' and '''1b''' show, estimates of recoverable oil depend fundamentally on knowing ''S''<sub>''wc''</sub>. Oil-based coring can provide reliable results and is an effective choice if its expense can be justified at the time a well is drilled. Electric logs can give vertical profiles, but as with ''S''<sub>''or''</sub>, require calibration for quantitative ''S''<sub>''wc''</sub> measurement.
[[Connate_water_saturation_evaluation|Connate water saturation]] is more variable (and less predictable) than ''S''<sub>''or''</sub>, with ''S''<sub>''wc''</sub> measurements ranging from > 50% in certain rock types to < 5% in unusual reservoir situations. Large variations within the producing intervals of major reservoirs are well documented.<ref name="r9">_</ref>


Deans and Shallenberger<ref name="r12" /> reported the first application of the SWCT method for measuring ''S<sub>wc</sub>''. As in the case when measuring ''S''<sub>''or''</sub>, the reservoir volume sampled is large and the test is nondestructive, which is especially important for a producing oil well. The tracers used in measuring ''S''<sub>''wc''</sub> are nonhazardous oxyhydrocarbons, so that no contaminated oil needs to be disposed of after the SWCT test. Most importantly, though, the test holds a high success rate—every known SWCT test for ''S''<sub>''wc''</sub> has yielded quantitative results.
As '''Figs. 1a''' and '''1b''' show, estimates of recoverable oil depend fundamentally on knowing ''S''<sub>''wc''</sub>. Oil-based coring can provide reliable results and is an effective choice if its expense can be justified at the time a well is drilled. Electric logs can give vertical profiles, but as with ''S''<sub>''or''</sub>, require calibration for quantitative ''S''<sub>''wc''</sub> measurement.
 
Deans and Shallenberger<ref name="r12">_</ref> reported the first application of the SWCT method for measuring ''S<sub>wc</sub>''. As in the case when measuring ''S''<sub>''or''</sub>, the reservoir volume sampled is large and the test is nondestructive, which is especially important for a producing oil well. The tracers used in measuring ''S''<sub>''wc''</sub> are nonhazardous oxyhydrocarbons, so that no contaminated oil needs to be disposed of after the SWCT test. Most importantly, though, the test holds a high success rate—every known SWCT test for ''S''<sub>''wc''</sub> has yielded quantitative results.
 
== Nomenclature ==


==Nomenclature==
{|
{|
|[[File:Vol5 page 0647 inline 001.png]]
|=
|average oil saturation in the reservoir, fraction of PV
|-
|-
|''S''<sub>''or''</sub>
| [[File:Vol5 page 0647 inline 001.png|RTENOTITLE]]
|=  
| =
|residual oil saturation, fraction of PV  
| average oil saturation in the reservoir, fraction of PV
|-
|-
|''S''<sub>''wc''</sub>  
| ''S''<sub>''or''</sub>
|=  
| =
|connate water saturation, fraction of PV  
| residual oil saturation, fraction of PV
|-
|-
|''V''<sub>''p''</sub>  
| ''S''<sub>''wc''</sub>
|=  
| =
|total pore volume, bbl
| connate water saturation, fraction of PV
|-
|-
| ''V''<sub>''p''</sub>
| =
| total pore volume, bbl
|}
|}


==References==
== References ==
<references>
<ref name="r1">Tomich, J.F., Dalton, R.L.J., Deans, H.A. et al. 1973. Single-Well Tracer Method to Measure Residual Oil Saturation. ''J Pet Technol'' '''25''' (2): 211–218. SPE-3792-PA. http://dx.doi.org/10.2118/3792-PA</ref>


<ref name="r2">Deans, H.A. 1971. Method of Determining Fluid Saturations in Reservoirs. US Patent No. 3,623,842.</ref>
<references />


<ref name="r3">Deans, H.A. and Majoros, S. 1980. The Single-Well Chemical Tracer Method for Measuring Residual Oil Saturation, Final report, Contract No. DOE/BC20006-18. Washington, DC: US DOE.</ref>
== Noteworthy papers in OnePetro ==


<ref name="r4">O'Brien, L.J., Cooke, R.S., and Willis, H.R. 1978. Oil Saturation Measurements at Brown and East Voss Tannehill Fields. ''J Pet Technol'' '''30''' (1): 17-25. SPE-6370-PA. http://dx.doi.org/10.2118/6370-PA</ref>
Cockin, A.P., Malcolm, L.T., McGuire, P.L. et al. 2000. Analysis of a Single-Well Chemical Tracer Test To Measure the Residual Oil Saturation to a Hydrocarbon Miscible Gas Flood at Prudhoe Bay. SPE Res Eval & Eng 3 (6): 544-551. SPE-68051-PA. [http://dx.doi.org/10.2118/68051-PA http://dx.doi.org/10.2118/68051-PA]


<ref name="r5">Sheely, C.Q. 1978. Description of Field Tests To Determine Residual Oil Saturation by Single-Well Tracer Method. ''J Pet Technol'' '''30''' (2): 194-202. SPE-5840-PA. http://dx.doi.org/10.2118/5840-PA</ref>
== External links ==


<ref name="r6">Thomas, E.C. and Ausburn, B.E. 1979. Determining Swept-Zone Residual Oil Saturation in a Slightly Consolidated Gulf Coast Sandstone Reservoir. ''J Pet Technol'' '''31''' (4): 513-524. SPE-5803-PA. http://dx.doi.org/10.2118/5803-PA</ref>
Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro


<ref name="r7">Nute, A.J. 1983. Design and Evaluation of a Gravity-Stable, Miscible CO2-Solvent Flood, Bay St. Elaine Field. Presented at the Middle East Oil Technical Conference and Exhibition, Bahrain, 14-17 March 1983. SPE-11506-MS. http://dx.doi.org/10.2118/11506-MS</ref>
== See also ==


<ref name="r8">Chang, M.M., Maerefat, N.L., Tomutsa, L. et al. 1988. Evaluation and Comparison of Residual Oil Saturation Determination Techniques. ''SPE Form Eval'' '''3''' (1): 251-262. SPE-14887-PA. http://dx.doi.org/10.2118/14887-PA</ref>
[[Residual_oil_evaluation_using_single_well_chemical_tracer_test|Residual oil evaluation using single well chemical tracer test]]
 
<ref name="r9">Donaldson, E.C. and Staub, H.L. 1981. Comparison of Methods for Measurement of Oil Saturation. Presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 4-7 October 1981. SPE-10298-MS. http://dx.doi.org/10.2118/10298-MS</ref>
 
<ref name="r10">Energy Information Administration (EIA). 1980. Annual Report to Congress, Volume 3, DOE/EIA-0173(79)/3, Washington, DC (July 1979).</ref>
 
<ref name="r11">Salathiel, R.A. 1973. Oil Recovery by Surface Film Drainage in Mixed-Wettability Rocks. ''J Pet Technol'' '''25''' (10): 1216–1224. SPE-4104-PA. http://dx.doi.org/10.2118/4104-PA</ref>
 
<ref name="r12">Deans, H.A. and Shallenberger, L.K. 1974. Single-Well Chemical Tracer Method to Measure Connate Water Saturation. Presented at the SPE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 22-24 April 1974. SPE-4755-MS. http://dx.doi.org/10.2118/4755-MS</ref>
</references>
 
==Noteworthy papers in OnePetro==
Cockin, A.P., Malcolm, L.T., McGuire, P.L. et al. 2000. Analysis of a Single-Well Chemical Tracer Test To Measure the Residual Oil Saturation to a Hydrocarbon Miscible Gas Flood at Prudhoe Bay. SPE Res Eval & Eng 3 (6): 544-551. SPE-68051-PA. http://dx.doi.org/10.2118/68051-PA
 
==External links==
Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro


==See also==
[[Designing_single_well_chemical_tracer_test_for_residual_oil|Designing single well chemical tracer test for residual oil]]
[[Residual oil evaluation using single well chemical tracer test]]


[[Designing single well chemical tracer test for residual oil]]
[[Connate_water_saturation_evaluation|Connate water saturation evaluation]]


[[Connate water saturation evaluation]]
[[Residual_gas_saturation_testing|Residual gas saturation testing]]


[[Residual gas saturation testing]]
[[PEH:The_Single-Well_Chemical_Tracer_Test_-_A_Method_For_Measuring_Reservoir_Fluid_Saturations_In_Situ]]


[[PEH:The Single-Well Chemical Tracer Test - A Method For Measuring Reservoir Fluid Saturations In Situ]]
[[Category:5.6.5 Tracer test analysis]]

Revision as of 10:54, 4 June 2015

The single-well chemical tracer (SWCT) test is an in-situ method for measuring fluid saturations in reservoirs. Most often, residual oil saturation is measured; less frequently, connate water saturation (Swc) is the objective. Either saturation is measured where one phase effectively is stationary in the pore space (i.e., is at residual saturation) and the other phase can flow to the wellbore. Recently, the SWCT method has been extended to measure oil/water fractional flow at measured fluid saturations in situations in which both oil and water phases are mobile.

Primary use

The SWCT test is used primarily to quantify the target oil saturation before initiating improved oil recovery (IOR) operations, to measure the effectiveness of IOR agents in a single well pilot and to assess a field for bypassed oil targets. Secondarily, it is used to measure Swc accurately for better evaluation of original oil in place (OOIP). Fractional flow measurement provides realistic input for simulator models used to calculate expected waterflood performance.

History

The first SWCT test for residual oil saturation (Sor) was run in the East Texas Field in 1968.[1] Patent rights were issued in 1971.[2] Since then, numerous oil companies have used the SWCT method.[3][4][5][6][7] More than 400 SWCT tests have been carried out, mainly to measure Sor after waterflooding.

The SWCT method has gained considerable recognition over the past few years because of increasing interest in the quantitative measurement of Sor. Some experts[8][9] consider the SWCT test to be the method of choice because of its demonstrated accuracy and reasonable cost.

Measuring residual oil saturation

Accurate Sor measurement is important because of a combination of basic problems in oil recovery. The industry still produces less than half the oil in the reservoirs discovered, and nearly all that oil is produced using traditional primary and secondary recovery methods.[10] Furthermore, as the cost of finding new reserves continues to increase, especially in the US, the oil remaining in old fields becomes a significant economic target for infill drilling and IOR projects.

In every target field, the quantity and location of the remaining oil must be determined. Fig. 1a illustrates the principle of material balance, as applied to an oil reservoir. The entire area of the graph represents the reservoir pore volume (Vp), which is known with varying degrees of uncertainty. The produced oil, corrected back to reservoir conditions, is the middle area; its accuracy, however, depends on how thoroughly production records have been kept.

The uppermost area is the connate water, which is known only as well as available methods and coverage of measurements allow. The lowermost area, the remaining oil, can be expressed as an average saturation of oil RTENOTITLE, if we accept the total pore volume Vp, produced oil, and Swc values as being accurate.

If a given field has been waterflooded, the fraction of the OOIP displaced by the water is a critical parameter. Testing for Sor in watered-out wells in the field can determine the maximum waterflood displacement efficiency. A significant difference between the material-balance So and the measured Sor would indicate the presence of bypassed oil. This would signify that parts of the reservoir had not been contacted by injected water, or had not received sufficient water throughput to reach Sor. This concept is shown in Fig. 1b.

A reliable in-situ measurement of Sor simultaneously defines the target for enhanced oil recovery (EOR) and allows estimation of the potential bypassed (mobile) oil in the field. This moveable oil is the target for infill drilling and/or flood sweep efficiency improvements.

Because Sor varies greatly with formation type, oil/water properties, and other variables that are not completely understood (e.g., wettability changes caused by water flood practices), Sor measurements range from < 10% to > 45%. There is no reliable way to predict Sor with acceptable accuracy for most reservoirs. Furthermore, measuring residual oil is not easy. Laboratory corefloods performed at other than native state wettability are unreliable.[11]

Well logs can give vertical profiles of Sor under optimal conditions, but their results are not absolute. Logs of all types require calibration by an independent method, which gives either a quantitative So at some point or an average So over some layer. Pressure cores or sponge cores can provide this calibration, but require a new well and are subject to saturation disturbances caused by mud filtrate invasion.

An advantage of the SWCT method is that it pushes tracers beyond damaged regions near the wellbore and into layers that are known to be at residual oil conditions. The tracers go where water is contacting the residual oil, as shown in Fig. 1b.

In an SWCT test, the formation volume sampled is large enough to be representative. A typical test quickly investigates hundreds of barrels of pore space in an existing watered-out well. The tracer-bearing fluids are produced back into the well without disturbing the formation, allowing further testing.

Measuring connate water saturation

Connate water saturation is more variable (and less predictable) than Sor, with Swc measurements ranging from > 50% in certain rock types to < 5% in unusual reservoir situations. Large variations within the producing intervals of major reservoirs are well documented.[9]

As Figs. 1a and 1b show, estimates of recoverable oil depend fundamentally on knowing Swc. Oil-based coring can provide reliable results and is an effective choice if its expense can be justified at the time a well is drilled. Electric logs can give vertical profiles, but as with Sor, require calibration for quantitative Swc measurement.

Deans and Shallenberger[12] reported the first application of the SWCT method for measuring Swc. As in the case when measuring Sor, the reservoir volume sampled is large and the test is nondestructive, which is especially important for a producing oil well. The tracers used in measuring Swc are nonhazardous oxyhydrocarbons, so that no contaminated oil needs to be disposed of after the SWCT test. Most importantly, though, the test holds a high success rate—every known SWCT test for Swc has yielded quantitative results.

Nomenclature

RTENOTITLE = average oil saturation in the reservoir, fraction of PV
Sor = residual oil saturation, fraction of PV
Swc = connate water saturation, fraction of PV
Vp = total pore volume, bbl

References

  1. _
  2. _
  3. _
  4. _
  5. _
  6. _
  7. _
  8. _
  9. 9.0 9.1 _
  10. _
  11. _
  12. _

Noteworthy papers in OnePetro

Cockin, A.P., Malcolm, L.T., McGuire, P.L. et al. 2000. Analysis of a Single-Well Chemical Tracer Test To Measure the Residual Oil Saturation to a Hydrocarbon Miscible Gas Flood at Prudhoe Bay. SPE Res Eval & Eng 3 (6): 544-551. SPE-68051-PA. http://dx.doi.org/10.2118/68051-PA

External links

Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro

See also

Residual oil evaluation using single well chemical tracer test

Designing single well chemical tracer test for residual oil

Connate water saturation evaluation

Residual gas saturation testing

PEH:The_Single-Well_Chemical_Tracer_Test_-_A_Method_For_Measuring_Reservoir_Fluid_Saturations_In_Situ