Humble Geochemical Services Division and Fluid Inclusion Technologies, Inc. are pleased to announce a new and advanced, integrated geochemical well logging program that utilizes both geochemical and fluid inclusion analyses. Fluid Inclusion Stratigraphy or FIS includes analysis of fluid inclusion volatiles and fluid inclusion petrography/microthermometry (FIS is licensed technology of Amoco Production Company). Other geochemical analyses will be used to identify and characterize source, shows, and reservoir rocks as well as any recovered or produced oil or condensate.
Western Canada Sedimentary Basin example showing three compartments (1) seal, (2) gas column, and (3) water column (Hadley et al., 1997).
Detailed Petroleum System and Reservoir
Continuity Analyses
This combined program will create a unique industry product for well,
field, and basin evaluation. The key components of petroleum system(s)
will be fully explored and characterized, when present, including (1)
source rocks, (2) timing of generation, (3) migration pathways, (4)
traps, and (5) seals. In addition reservoir continuity will be assessed
in stacked or multiple payzones. While not every well or prospect will
have these components present, this program provides the means to
detect and evaluate these components when they are encountered.
When integrated with other geological and
geophysical data as well as nearby well analysis,
present and future prospects and plays can be high-graded with
these results.
Incorporation of this enhanced geochemical well log into petroleum systems analysis includes characterization of:
The Approach
Geochemical methods have been widely applied to source rock and oil studies primarily for oil potential, maturity, and correlation purposes (for example, see Hunt (1995) or Tissot and Welte (1989)). More recently these techniques have been applied to finding overlooked payzones and identifying the quality of pay expected to be produced (Jarvie et al., 1995). This can include prediction of best completion zones and the likely API gravity or viscosity of the oil in payzones. Furthermore, these techniques can be applied toward the evaluation of stacked sand payzones for both quality and connectivity. These techniques work especially well with frozen SWC where light hydrocarbons (C4-C12) are preserved for detection and evaluation of condensate pay. API gravity and pour points (especially for waxy crude oils) can also be estimated from recovered reservoir rock samples.
When source rocks are identified, they can be characterized in detail and correlated to oils. Advanced geochemical techniques permit the evaluation of timing of oil generation from immature source rock samples or recovered oil samples.
Fluid inclusion stratigraphy (FIS) provides a detailed evaluation of fluids trapped as inclusions in rock samples. FIS allows the dimension of time to be added to the equation, as these crystallographically entrapped fluids may sample several chemically distinct charges, and may preserve traces of fluids no longer in the pore system. Fluid inclusions are not subject to alteration or devolatilization during sampling from depth or storage, hence they are chemically representative of the pore fluid at depth. FIS data can be used to delineate and characterize payzones, infer migration pathways, characterize seals, and evaluate potential for proximal pay (Hadley et al., 1997; Hall et al., 1997).
What is unique about this enhanced geochemical well logging is (1) the combination of old and new geochemical techniques with fluid inclusion stratigraphy and microthermometry, and (2) completion and integration of all analysis under a simple, cost effective pricing structure.
Sampling Requirements
Analyses are applicable to cuttings, SWC, core, outcrop material
sampled at a scale appropriate for the resolution desired. Oil samples
recovered from RFT, DST, or other testing operations or from the
wellhead are used from the oil analyses.
The primary advantage of this enhanced logging approach is that a more complete understanding of the petroleum system is obtained through characterization of all sources of organic matter within the rock:
How to Obtain an Enhanced Geochemical Well Log
Step One - Initial
Contact
New clients are encouraged to consult with Humble and FIT staff during
the early stages of project development to discuss the goals of the
analytical program and to set up sample collection, packing, and
shipping procedures.
Step Two -
Sampling
For basic geochemical analysis well cuttings should be collected from
the shaker and lightly washed with water. Samples should be bagged or
canned wet and should never be dried.
Samples of the drilling fluid and any organic well additives should
also be taken. These are used for "background" analysis.
Sidewall core (SWC) samples should be wrapped in foil and sealed in a jar. The jar should then be immediately stored in an ice chest or container with dry ice added. This will preserve light hydrocarbon to about butane (C4) when present. Any container filled with dry ice must have vent holes if tightly sealed as dry ice sublimes, i.e., converts, directly to gas. Venting will prevent any excess pressure build-up.
Oil samples recovered from testing operations (RFT, DST, etc.) or initial production oil should be placed in SWC jars or our special oil containers. Jars and containers should be taped shut to prevent loosening of the seal. These containers are then inserted into special shipping containers.
Sample containers - cans, bags, jars, etc. - are available from Humble Geochemical Services.
Sample analysis intervals are generally 10 ft. with only every 30 or 60 ft. being analyzed. Samples are in-filled when interesting results are derived from the initial analyses or when well logs indicate intervals of interest.
Fluid Inclusion Stratigraphy involves crushing rock material under vacuum and measuring evolved volatile compounds with a bank of quadrupole mass spectrometers. The following information and procedures should be kept in mind when sampling for this technology.
The technique is applicable to cuttings, core and outcrop samples, but all samples must be reduced to cuttings-sized rock material. Wells drilled with any mud system can be analyzed, including oil-based systems. Approximately 1 gm of clean rock material is needed for each sample. Most samples need to be at least "lightly washed" prior to analysis--even those collected as "washed samples." Therefore, it is best to send enough material to allow for loss during further washing. It is recommended that "clean lith cuts" of drill cuttings be provided for FIS analysis as these samples require the least amount of additional preparation. Some clients prefer to subsample and wash drill cuttings in-house prior to shipment to our facility.
The sampling interval is dependent on the question to be answered. Large-scale, multi-well, regional studies can often be run at 60 ft (20 m) spacing. Our suggested sampling interval for general well studies is 30 ft (10 m). Pay-delineation studies, reservoir-scale studies or other applications involving rapidly changing fluid chemistries should be sampled at the tightest possible spacing, depending on sample availability (e.g., 1-3 ft). A maximum of 575 samples can be analyzed for a given well.
Step Three -
Supporting Information
Supporting information is invaluable for interpreting results of
geochemical well logs. Integration of the following information
significantly increases the value of the final product:
Analytical Program
The analytical program is designed to provide maximum data and flexibility at minimum expense. Some analyses will be provided on all samples only depending on the sampling interval requested. In-fill sampling and detailed analyses will be completed at no additional charge except for vitrinite reflectance and Iatroscan analyses. Up to 575 samples can be analyzed for FIS per well. The following data and results are included:
All Samples
Total organic carbon (TOC) - all samples depending on sampling
interval
Rock-Eval analysis - all samples depending on
sampling interval
Fluid Inclusion analysis - all samples depending on sampling
interval
Selected or High-graded Samples
Thermal extract gas chromatography fingerprints (stained samples and
any frozen SWC)
API prediction (reservoir rocks only)
Light hydrocarbon analysis of oils (RFT, DST, production)
Extraction (source rocks or selected stained rocks)
Fractionation into saturates, aromatics, resins, asphaltenes (source
rock extracts, selected stained rock extracts, and oils)
Biomarker analysis (source rocks, selected stained rocks, and oils)
Kinetic analysis (immature source rocks only)
Options:
Interpretation
Maturity profile from vitrinite reflectance
Iatroscan profile of rock extracts
Delivery of Analytical Results and Final Report
Data will be presented in digital and graphical forms including geochemical and fluid inclusion logs by depth. Fingerprints (gas chromatographic traces) and biomarker traces will be plotted in full scale reports and pasted into interpretive reports as needed or appropriate. Graphical display of geochemical data will be provided whenever feasible as an interpretive and presentation aid.
All data, graphics, chromatograms, and reports are available by electronic data transfer. This may be completed by email or delivery of computer media. Of course, hard copy reports can also be supplied by fax when requested and will be delivered as a final report.
Immediately following analysis the analytical results are available as ".las" formatted ASCII files and can be transferred electronically anywhere in the world via e-mail. A hard copy of the final report that includes an interpretive summary, photomicroscopy, chemical depth profiles, individual mass spectra for each sample analyzed for FIS, and a 24x36in color display of the results will be issued shortly thereafter and shipped via priority post.
Enhanced Geochemical Well Log
Analysis:
Program and Individual Sample Costs
Price Schedules for Enhanced Geochemical Well Log analytical services are detailed below.
These prices are inclusive of all TOC, Rock-Eval, and FIS on all samples based on the sampling interval selected. These results will include additional detailed analyses of source rocks, stained rocks, and oil samples as selected by Humble Geochemical Services at no additional charge. For example, if an immature source rock is located, it will be extracted, the extract fingerprint and saturate biomarkers completed, and kinetics completed at no additional charge (if the source rock results can be released in 0-12 months). If oil stained rocks or oils are recovered, selected rocks will be extracted and both extracts and oils fingerprinted including biomarker analysis at no additional charge (if the oil or extract data can be released in 0-24 months). Vitrinite reflectance, Iatroscan analysis, Fluid Inclusion Microthermometry, basin modeling, and interpretation are charged separately.
Identification and prediction of oil quality from fresh water basin cuttings analysis (a) thermal extract gas chromatographic fingerprint (left) and (b) predicted API gravity chart (right)
Notes:
References
Hadley, Scott W., , S. Michael Sterner, and Wells Shentwu, 1997, Hydrocarbon Pay Delineation and Product Characterization with Fluid Inclusions: Examples from East Coast Canada and Western Canada Sedimentary Basin, in Can. Well Log. Soc. in site, Vol. 1, No. 3, p.2-4.
, Wells Shentwu, S. Michael Sterner, and Paul D. Wagner, 1997, Using Fluid Inclusions to Explore for Oil and Gas, Hart's Petroleum Engineer International, No. 11, p. 29-34.
Hunt, John M., 1995, Petroleum Geochemistry and Geology, 2nd edition, W. H. Freeman and Company, New York, 743p.
, Joseph T. Senftle, William Hughes, Leon Dzou, James J. Emme, and , 1995, Examples and New Applications in Applying Organic Geochemistry for Detection and Qualitative Assessment of Overlooked Petroleum Reservoirs, in Organic Geochemistry: Developments and Applications to Energy, Climate, Environment, and Human History, Joan O. Grimalt and Carmen Dorronsoro, eds., 17th International Meeting on Organic Geochemistry, pp. 380-382.
, A. S. Ahmed, and , 1990, Gas Chromatography as a Development and Production Tool for Fingerprinting Oils from Individual Reservoirs: Applications in the Gulf of Mexico, in GCSSEPM Foundation Ninth Annual Research Conference Proceedings, p. 263-282.
Tissot, B. P. and D. H. Welte, 1984, Petroleum Formation and Occurrence, 2nd edition, Springer-Verlag, Berlin, 699p.
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Services, Inc. All rights reserved.
Revised: