General Field Information |
| Produces Oil: Yes Produces Gas: No |
| Geologic Province: |
Central Kansas Uplift |
| Exploration Method: |
Interpretation of sparse subsurface and seismograph data |
| Surface Formation: |
Primarily Niobrara (cretaceous) |
| Oldest Formation Penetrated: |
Arbuckle |
| Drilling Casing Practices: |
All wells were drilled with Rotary Tools. After setting surface casing as required, drilling continued through the Conglomerate sand section. The Toronto, Lansing-Kansas City zones and Conglomerate Sand were drillstem tested during drilling operations. Completion involved setting production casing through the Conglomerate Sand reservoir and perforating within the porous interval above the water level. Most of the wells were completed naturally by perforating the Conglomerate Sand and swabbing the wells in. Acid treatment was necessary in two of the wells. |
| Electric Logging Practices: |
At total depth all producing wells were logged, using a Radiation Guard Log and Borehole Compensated Sonic Log. |
| Comments: |
Other Shows: Based on drillstem test and log data, Lansing-Kansas City zones "E"-"F", "G", and "I" appear to be productive in isolated areas of the field. |
| Discussion: |
The Natoma East Field is a closed symmetrical anticlinal feature of post-Mississippian age located on the Northeast flank of the Central Kansas Uplift. Axis of the structure trends northwesterly as does the large Central Kansas Uplift on which it is found.
The amount of closure increases with depth. Structural relief on the shallow Stone Corral Anhydrite is much less than on the Heebner Shale. Closure on the Heebner Shale is 23 feet, 33 feet on the Conglomerate Sand and probably as much as 84 feet on the Simpson.
The Natoma East Field was discovered by completion of the Locke 1-19 in January 1978 as an oil producer from the Conglomerate Sand. The discovery also recovered oil on drillstem tests of the Toronto and at least four Lansing-Kansas City zones. Five additional conglomerate producers were completed on the Locke and Locke Brothers leases by October, 1978. Initial reported water production ranged from no water to 65% water. Locke 5-19 tested water from the Conglomerate Sand and was made into an injection well in August of 1978. All produced water then went into this well. Remaining Conglomerate Sand development occurred with the completion of the Locke 6-19 in July 1979 and the Locke Brothers 3-19 in June 1980. Dry Holes were drilled to the east in 1978, the south in 1981 and to the north in 1980 and 1983.
The Graham-Michaelis Locke 1-18, an old well work over, which swab tested a trace of oil from several zones in the Lansing-Kansas City in mid-1980 was converted to a Conglomerate Sand injection well in December 1980. Produced water was then split between the two injection wells.
The Graham-Michaelis 7-19 Locke was drilled in July 1981 and encountered both the Lansing-Kansas City and Conglomerate Sand very low on structure. It was completed in August 1981 as an open hole Arbuckle salt water disposal well. All produced water was then disposed of into this well from September 1981 to April 1984 when some of the produced water was again injected into the Locke 1-18.
The first Lansing-Kansas City production occurred with the recompletion of the Locke 5-19 in September 1981 for 95 BOPD + 111 BWPD from zones "B" and "K". In October 1984 the Locke 6-19 was recompleted through perforations in the Toronto and Lansing-Kansas City zones "B" and "K". Based on drillstem test and log data, the Toronto should be productive on the Locke lease in an area bounded by wells 1-19, 2-19 and 6-19. Lansing-Kansas City zone "B" should be productive in all existing oil wells. Lansing-Kansas City zones "E-F", "G", "I" and "K" will be productive only in isolated areas of the field. |
|
| Depth Top: |
3598 feet |
| Geological Age: |
Pennsylvanian |
| Depositional Environment: |
Mississippian, Maquoketa and Viola rocks are absent by removal as a result of uplift and erosion prior to Pennsylvanian sedimentation. Conglomerate sand and vari-colored chert conglomerate was deposited on a pre-Pennsylvanian Simpson surface of Ordovician Age. Limestone and shale of the Marmaton Group (Desmoinesion Series) overlie the Conglomerate Sand. |
| Formation Lithology: |
The Conglomerate reservoir rock is a medium to coarse grained, angular, well sorted, friable, clear to frosted quartz sand along with varying amounts of vari-colored cherts. Sand clusters have visual porosity with oil staining in the samples. Most of the wells have excellent porosity. |
| Formation Geometry: |
The Pennsylvanian Conglomerate Sand is about 88 feet below the base of Lansing-Kansas City in the Natoma East Field. It varies in thickness from 38 to 62 feet and is about 49 feet thick in the center of the field. Based on log calculations and drillstem test data, it is thought to have an oil-water contact of about -1560 subsea. Net pay in the productive wells range from 10 to 21 feet or an average of 14 feet. |
| Trap Type: |
Structural (over 30' closure) |
| Depth Top: |
3297 feet |
| Geological Age: |
Pennsylvanian |
| Depositional Environment: |
The Lansing Group (Missouri Series) consists of alternating beds of limestone and shale. There are ten horizons referred to as the "A","B", "C-D", "E-F", "G", "H", "1", "J", "K" and "L" zones with an overall thickness of approximately 251 feet. The shale and limestone beneath the Lansing-Kansas City has an approximate thickness of 34 feet and is placed in the Pleasanton Group. The Pleasanton Group overlies approximately 54 feet of limestone and shale belonging to the Marmaton Group (Desmoinesian Series). |
| Formation Lithology: |
The Lansing-Kansas City "B" and "K" Zones are white to gray fine crystalline, fossiliferous and slightly oolitic limestone with fair pinpoint to vugular porosity. |
| Formation Geometry: |
The Toronto and Lansing Kansas City Section of Pennsylvanian age has a gross thickness of about 282 feet in the Natoma East Field. They are composed of alternate beds of limestone and shale. The Toronto top is about 19 feet below the Heebner Shale and 29 feet above the Lansing Kansas City Zone "A" top. It is a 14 foot limestone bed with a net pay of 4 to 5 feet. Limestones of the Lansing Kansas City "B" and "K" zones are approximately 15 feet thick with an average pay thickness of 4 feet in the "B" zone and 3 feet in the "K" zone. |
| Trap Type: |
Structural (over 30' closure) |
