Field Desorption

Exploration

 

Laboratory Analyses

 

Knowledge Base

 

Rock Mechanics

Gas Shales

 
Field and laboratory Analyses of Gas Shales

CBM Solutions is the industry leader in assessing gas shales.  We have pioneered field desorption and adsorption analyses of gas shales.  We have worked extensively with producing US shales and all the important potential gas shales in Western Canada including the Exshaw/Bakken, Nordegg, Duvernay, Second White Specks, Doig, Montney and Shaftesbury and other strata. 

CBM Solutions Gas Shale Evaluation Protocol (GSEP) is a comprehensive set of analyses specifically designed to evaluate the gas shale potential of fine grained strata. The analytical techniques are designed for purpose and are based on the recognition that conventional rock analyses and coalbed methane protocols are, for the most part, not applicable to tight, fine grained rocks. We have further refined our methodologies based on extensive field and laboratory studies such that our protocols are optimized for specific gas shales with the recognition that gas shales are diverse and heterogeneous reservoirs.

The Gas Shale Evaluation Protocol is designed specifically to: 1) determine the gas in place (sorbed, free and solutions gas) throughout the stratigraphy; 2) quantify matrix and where possible bulk permeability and stress sensitivity of permeability; 3) characterize in situ fractures; 4) select zones optimal for fracturing; 5) evaluate borehole stability; and 6) determine zones for horizontal drilling and completions. Our protocol begins with assisting where necessary with well design, continues at the well site, through the laboratory and numerical analyses and culminates with successful well development.

We recognize that the timing is everything! It is our goal to provide key data for zone evaluation, frac zones selection and frac design within a time frame that enables our clients to utilize the data while the rig is still on site. Our time sensitive protocol includes providing total gas in place, porosity, mineralogy and rock mechanics data and where possible stress sensitive permeability. Since we do almost all analyses in house; we control the quality, timing and reporting of analyses.

WELL SITE SERVICES- Our contributions to the well site begin in the office where our experienced staff are available to our clients to assist in the design and optimizing of well drilling, testing and completion programs. On the well site we handle, describe and perform fracture analyses, photography, gamma ray log, preserve and canister samples for desorption and total gas analyses. Gas samples are collected throughout the desorption process and integrated for average gas composition values. Well site sample and fluid preservation is critical for further analyses. We can utilize cuttings, side wall, wire line retrieval core and conventional core. On site we determine the uniaxial compressive strength of representative core specimens using out portable point load tester and cuttings samples throughout the well are collected and preserved for near real time mineralogical and organic carbon analyses. On site samplers are selected, preserved and analyses began for our proprietary PRODUCTION ISOTHERM.

TOTAL GAS STORAGE- Gas storage in gas shales includes gas in the adsor-----------ee states and in solution. Using our preserved well site samples effective, total porosity and water saturation are determined on representative samples. Adsorption isotherms and production isotherms are collected on all major strata. Our analyses include measurement of porosity and permeability of methane or other gases using our proprietary methodologies. Pore size distribution is determined by a variety of gaseous
methods, as well as high pressure Hg intrusion (Hg porosimetry).

PERMEABILITY- Although bulk permeability of fractured reservoirs requires field tests, in many gas shales the matrix permeability/diffusion is limiting. We collect crushed sample permeability and diffusion data as a matter of course during porosity
determination and from Hg intrusion data, however, we advocate permeability measuring under reservoir stress condition and we quantify the stress sensitivity of permeability which allows us to predict the producability of the strata.

INORGANIC GEOCHEMISTRY- Inorganic geochemistry starts with mineralogical analyses by x-ray diffraction.  We quantify the mineralogy by Rietveld analyses where possible and provide the data in a format suitable for log calibration.  Where needed, additional analyses of the elemental chemistry, mineral fabric by SEM/EDS, thin section analyses, fluid sensitivity and particle size distribution may be undertaken.

ORGANIC GEOCHEMISTRY- The adsorption capacity of fine grained rocks is closely correlated with the abundance, type and maturity of the organic matter..  Our protocol using a combination of total carbon, Rock Eval and organic petrology with  vitrinite reflectance analyses provides data that can be tied to adsorption data and integrated through the stratigraphy and laterally via appropriate  calibration of well logs.  Carbon and hydrogen isotopic analyses of gas samples may also be performed if deemed necessary.

FRACTURE ANALYSES- Our fracture description and analyses protocol is integrated with photographs and three dimensional analyses and provides data that can be used for quantitative analyses using industry standard software.

ROCK MECHANICS- Reservoir access is key to exploitation of unconventional gas reservoirs.  CBM Solutions 'geomechanical stratigraphy' program is specifically designed to provide our clients with the necessary rock mechanical properties critical for borehole stability and frac design.  When our geomechanical stratigraphy is linked with our stress sensitivity permeability analyses, our clients are armed with the key tools for screening gas shales for exploration and exploitation through optimization of drilling and completions.  All mechanical tests are carried our using a servo controlled triaxial apparatus under prescribed stress states and pore pressure providing compressive strength, all relevant moduli (Young's, Shear Bulk), Poisson's Ration, Biot's poroelastic parameter etc.  We can deform whole core samples ranging from 1 inch to 4 inches in diameter, alleviating the necessity of recoring existing core.  We measure ultrasonic compressional and shear-wave velocities to collect dynamic elastic moduli that can be used for calibration of sonic logs.

DATA INTEGRATION- CBM Solutions experts work with our clients to integrate the myriad of engineering and geological data into a comprehensive exploration and development program giving our clients the technical advantages necessary for successful exploration of unconventional petroleum reservoirs,

 

 
 

Tel: (403) 510 8154 Address: 621-37 Avenue NE, Calgary, Alberta, T2E 2M1 E-mail: cbm@cbmsolutions.com
Tel: (403) 510 8154 Address: B3 7120 West 117th Ave, Broomfield, CO: 80020 E-mail: cbm@cbmsolutions.com