BAKKEN STUDY AND DATABASE

This study and database includes the U.S. portion of the Bakken depositional basin (within the Williston Basin) extending from R45E in Montana to R76W in North Dakota, and from T139N to T164N. Important aspects of the database include: picks in the Bakken, including lower, middle, and upper Bakken members; feet of effective resistivity and maximum resistivity for both Bakken Shales. The Lodgepole database includes various picks within the formation that show the clinoform nature of Lodgepole deposition and the presence of paleostructures.

Number of wells: 3,950

 

LODGEPOLE DATABASE

The Lodgepole database includes various picks within the formation that demonstrate the clinoform nature of Lodgepole deposition and the presence of paleostructures. Carbonate buildups (mounds) within the lower and middle Lodgepole can be mapped using multiple picks within the database. This database conforms to the Bakken database and extends from R45E in Montana to R76W in North Dakota, and from T139N to T164N. A comprehensive north-south cross section with wireline log picks accompanies this database.

Number of wells: 3,950

 

MISSISSIPPIAN DATABASE

This North Dakota database extends from R76W to R106W and T139N to T164N (Canadian border) and includes picks from the top of the Lodgepole to the top of the Charles. Important aspects of this database include subdivision of the Mission Canyon Formation into the following intervals: Tilston, Landa 1, Landa 2, Wayne, Glenburn, Mohall, Sherwood, Bluell, Coteau, Dale, and Rival. This database also includes the following Ratcliffe intervals in the central basin: Midale, Berentson, Alexander, Goose Lake, and Charles C. The database can be divided into east flank and central basin databases at lower cost.

Complete Mississippian Database

Number of wells: 10,900

East Flank Database

Number of wells: 4,800

Central Basin Database

Number of wells: 6,100

 

GLENBURN-MOHALL-FRYBURG STUDY AND DATABASE

This North Dakota study and database is a specialized analysis of the Glenburn and Mohall beds of the Mission Canyon Formation. Special aspects of the database include: percent anhydrite data for both intervals, intraformational picks for exploration in the Fryburg interval, and other picks within these intervals that detail paleostructural relationships.

Number of wells: 3,500

 

RIVAL STUDY AND DATABASE

The Rival study and database extends from T139N to T164N and from R76W to R57E. The study and database focus on Rival shoreline trends in Burke and Mountrail counties and the Rival shoal, or bank play, in the Central Basin (Billings, McKenzie, and Williams counties). The study details depositional facies and

controls on reservoir development. The database includes detailed picks within the Rival related to base level changes (sequence stratigraphy). The database includes detailed picks along the Nesson Anticline.

Number of Wells: 6,500

 

RATCLIFFE STUDY AND DATABASE

This study and database extends from just west of the Nesson Anticline to west of Lustre Field in Montana. The database breaks out the following Ratcliffe Members: Berentson, Alexander, Flat Lake, Charles C, and Lustre. Important aspects of the database include wireline log picks that show the relationship of paleostructure to production in Ratcliffe beds.

Number of wells: 5,500

 

CHARLES SALT DATABASE

This extensive database covers the North Dakota and Montana portions of the Williston Basin where Charles Salts were deposited. Important aspects of this database include picks for all Charles Salts and salt splits (e.g. Charles 5a, 5b, and 5c), and depositional solution edges. These data can be used to map the structural evolution of the basin during Mississippian time.

Number of wells: 9,000

 

PERMO-TRIASSIC-JURASSIC SALT DATABASE

This large database includes salt picks and the depositional and solution edges of the Opeche, Pine, Saude, and Dunham salts in the U.S. portion of the Williston Basin (North Dakota, South Dakota, and Montana). Important is the subdivision of Opeche and Pine salts into subsalt intervals (basal Opeche, Opeche A, B, and C, Pine 1-6 salts, and upper and lower Saude salts).

Number of wells: 7,500

 

NORTH DAKOTA SHALLOW DATABASE

This database includes wireline log picks from the top of the Charles to the Greenhorn (Cretaceous). Many of the formational picks can be used to show the structural evolution of the basin during Pennsylvanian, Permo-Triassic, Jurassic, and Cretaceous time. Important are Tyler and Dakota picks, and the Greenhorn pick (commonly used by geophysicists).

Number of wells: 10,900

 

WILLISTON BASIN DEEP DATABASE

This database incorporates picks from the Precambrian to the top of the Charles. Important picks include: Deadwood, Winnipeg, Red River, Silurian, Devonian, and major Mississippian wireline log tops. Isopach maps indicate variations in the tectonic and depositional history of lower Phanerozoic sediments.

Number of wells: 7,500

 

 

 

  

Hendricks and Associates, Inc. has constructed several digital tops databases and stratigraphic studies to aid companies in exploration and production projects in the Wyoming - Northwestern Colorado area. Digital header data is available for a nominal charge.

 

Cretaceous Database

This database extends from the Moxa Arch to the Rawlins Uplift and from T8N in Colorado to T24N in Wyoming. A subset of the database extends north along the Moxa Arch into the LaBarge area (from T24N to T28N and from R108W to R113W). The database includes picks from the Mowry to the top of the Cretaceous. Special aspects of the database include: numerous picks in the Hilliard Shale which can be used for time stratigraphic mapping, various picks in the Frontier Formation following the nomenclature in the Big Piney-LaBarge complex area, subdivision of the Mesaverde east of the Rock Springs Uplift into members and tongues of the Blair, Rock Springs, Ericson, and Almond Formations, and a lithostratigraphic pick in the upper Lance which defines early Laramide structural movement.

Regional stratigraphic analysis requires an extensive database. Formation tops, obtained from subsurface wireline logs, can provide exploration geologists and geophysicists with critical data for reconstructing paleostructural and depositional trends. Most companies, however, do not have the staff or time to dedicate to this endeavor.

Hendricks and Associates, Inc. constructed a digital tops data file of the Green River, Great Divide, Washakie, and Sand Wash Basins of southwestern Wyoming and northwestern Colorado. This area has long been a focus of exploration for oil and gas, and will continue to be a focus of natural gas exploration as companies supply western U.S. pipelines. The database was completed using the following parameters:

- All commercially available wireline logs

- All major Upper Cretaceous formation tops were picked. The members and tongues of the Mesaverde Group east of the Rock Springs Uplift were also included. Original participating companies agreed on formation boundaries.

The Green River portion of the database covers the area from the axis of the Rock Springs Uplift to the Wyoming overthrust (T12N-T28N and R104W-R114W). The Great Divide-Washakie portion covers the area from the axis of the Rock Springs Uplift to the Rawlins Uplift and the Sand Wash Basin of Colorado (T12N-T26N and R90W-R102W in Wyoming and T8N-T12N and R90W-R102W in Colorado).

Number of wells: 6,500

 

ALMOND STUDY AND DATABASE

The Almond Study and Database extend from T8N to T24N and from the Rock Springs Uplift to the Rawlins Uplift (R91W-R101W). The database contains picks in the lower Lewis Shale, the upper marine Almond and the lower non-marine to marginal marine Almond. Important aspects of the database are:

- Identification of transgressive cycles and picks related to upper marine Almond sandstones,

- For the upper and lower (non-marine) Almond, there are gross and net sandstone data, net resistivity, and net porosity picks for all sandstones five feet or greater in thickness.

The Almond Formation is the uppermost member of the Mesaverde Group in the Great Divide and Washakie Basins of Wyoming, and the Sand Wash Basin of Colorado. The Almond is oil and gas productive at Patrick Draw and gas productive in fields such as Wamsutter, Desert Springs, and Wild Rose. The upper (marine) Almond is an important exploration target because of its high production rates. Published geologic information on the Almond is limited indicating a need for detailed stratigraphic and diagenetic analyses, especially in sparsely drilled areas. Integration of core and petrographic data with regional trends obtained from subsurface wireline logs should increase drilling success.

Hendricks and Associates, Inc. conducted a detailed stratigraphic and diagenetic analysis of the Almond Formation in the Great Divide, Washakie, and Sand Wash Basins. They did the following to complete the study:

- Described the major Almond lithofacies on outcrop and tied these lithofacies into subsurface cores and logs.

- Described in detail all publicly available cores (142 cores) noting lithofacies, porosity, depositional facies and other stratigraphic parameters.

- Conducted detailed petrographic analyses on reservoir and non-reservoir facies using thin sections, S.E.M., and X-ray analyses. Close attention was paid to authigenic clays and their relationship to reservoir productive capacity.

- Constructed a digital tops data file which included the top and base of the upper (marine) and lower (non-marine) Almond, net sandstone data in both the upper and lower Almond sandstones, net porosity data, resistivity data, and depositional and shoreline trend data. All commercially available logs within the study area were used (approximately 2800 logs).

- Developed exploration concepts using depositional and diagenetic models.

The final report includes a detailed summary of core lithofacies, petrographic analyses, and trend maps.

A one day field session was conducted near the end of the study to examine Almond and other Mesaverde outcrops along the east flank of the Rock Springs Uplift. Purchase of the Almond Study will entitle the participating company to the same one day field trip. The cost for lodging and transportation for company representatives will be borne by the participating company.

Number of wells: 2,800

 

LEWIS STUDY AND DATABASE

Each producing Lewis sandstone interval, and all prospective sandstone intervals were picked. Important aspects of the database include: the ability to map discrete Lewis sandstone packages in the Red Desert, Washakie, and Sand Wash basins. Gross and net sandstone values for each stratigraphic interval provided a means to identify depositional trends and potential plays. The aerial extent conforms to the Almond Database.

The Lewis Formation is an important exploration target because of its high oil and gas production rates. The Lewis is also a secondary exploration and production target where deeper Mesaverde sandstones are primary objectives.

Published geologic information on the Lewis is limited. Work by Van Horn and Shannon (1989) and Winn (1987) indicates that the Lewis was deposited in submarine environments. The clinoform geometry of the sandstone and shale "depositional wedges" described in these papers is easily documented. However, no commercially available database has correlated and picked the tops and bases of clinoforms in the Great Divide, Washakie, and Sand Wash Basins.

Further, detailed stratigraphic and diagenetic analyses of the Lewis is sparse. Integration of subsurface core and petrographic data with regional trends obtained from subsurface wireline logs should increase drilling success.

Hendricks and Associates, Inc. conducted detailed stratigraphic and diagenetic analyses of the Lewis Formation in the Great Divide, Washakie, and Sand Wash Basins. They did the following to accomplish these analyses:

- Described the major Lewis lithofacies on outcrop and tied these lithofacies into subsurface cores and logs.

- Described in detail all publicly available cores noting lithofacies, porosity, depositional facies, and other stratigraphic parameters.

- Conducted detailed petrographic analyses on reservoir and non-reservoir facies using thin sections and S.E.M. analyses. Close attention was paid to authigenic clays and their relationship to reservoir productive capacity.

- Constructed a digital tops data file which includes the top and base of the Lewis Formation and major clinoform and sandstone intervals. All commercially available logs within the study area was used (approximately 1800 logs).

- Developed exploration concepts using depositional and diagenetic models.

The final report includes a detailed summary of core lithofacies, petrographic analyses, and trend maps.

A one-day field session was conducted at the end of the study to examine Lewis Formation and Mesaverde outcrops along the flanks of the Rawlins uplift. Purchase of the Lewis Study will entitle the participating company to the same field trip. The cost of lodging and transportation for company representatives will be borne by the participating company.

Number of wells: 1,950

Wyoming - Northwestern Colorado