A Note on Petroleum Occurrences in the Kindersley District, Southwestern Saskatchewan J E. Christopher I Christopher, J.E. ( 1999): A nolc on petroleum occurrences in the Kindersley district, southwestern Saskatchewan: in Summary of Investigations 1999. Volume I. Saskatchewan Geological Survey. Sask. Energy Mines, Misc. Rep. 99-4.1. 1. Introduction shows in the context of the Success Formation within the general detrital basin on the Mississippian erosion There are few regions in Saskatchewan that offer as surface. many petroleum exploration options as the Kindersley di strict. It is productive in: I) natural gas from the Upper Cretaceous Judith River Formation, 2) petroleum and natural gas from the Lower 2. Lithology Cretaceous Viking and Mannville formations, 3) The Kindersley district is areally delineated by the petroleum from the Jura-Cretaceous Success distribution of deposits that infill and blanket the Formation, and 4) Mississippian Bakken formations. erosion surface on the Mississippian Madison Oil shows are widespread in the Mannville, Success, Formation. These deposits are described regionally by Bakken, and Upper Devonian Birdbear formations. Maycock (1967) and detailed by White (1969) for the This note examines the general setting of these oil Hoosier Oilfield. Maycock ( 1967, p 18) noted the presence of two lithologic types: "cherty breccio-conglomerates" as in the core from the Imperial Warrior l0-29-27-25W3 well (depth: 923.5 to 938.8 m), and ''whitish sandstones", unlike those of the overlying Mannville, cored in the Tidewater Plato Crown 9-22-24- l 9W3 well (depth: 831 .5 to 857.4 m). Core data from the Success Formation are relatively scattered, but representative well cuttings are available from most wells in the district. These samples are distinguished by the predominance of white porcelanite, tripolitic chert, grey chalcedony, silica replaced oolitic and crinoidal bioclasts, fine­ grained quartzose sandstone, and tan to red-brown, coarse-grained, sideritic spheroids as aggregations in very fine grained quartzose sand. It is apparent that much of the white siliceous and kaolinitic matrix-forming clays has been washed out of the well cuttings in the cleaning. Quartzose sandstone and coal, where present, are also recovered. In some localities, as at Imperial 100 SO O 100 200 mil•• ...... l&W1 I I Centerfi eld 13-10-26-21 W3, 160 80 O 160 320 km indurated white, magenta, and yellow claystone interbeds in Figure I - Location map ofstudy area. quartzose sandstone and cherts ' J.E. Christopher, Ph .D .. r. Gcol., Geological Consultant. Regina, SK. Saskatchewan Geological Survey 33 are indicated. Heavy oil staining in the samples is Madison Formation, is moot. widely distributed throughout the Kindersley district, but mostly in the cherty, pore-moldic deposits, The quartzose sandstone, as typified by the 14 .6 m of indicating thereby a preferential permeability. core from Consumers Hartog Whiteside l I -9-30- 26W3, is white with red patches, kaolinite-indurated Whereas incorporation by reworking of one lithologic and fine and very fine grained. It includes subordinate type into the other is common, at some localities either quartzose silt, abundant angular, cherty pebbles, and can be dominant. In places, the basal contact of the brown, coarse-grained siderite-cemented aggregates of cherty facies may be difficult to distinguish from fine-grained, quartzose sand. Bedding is fragmentary, underlying karsted Madison limestone. For instance, at and the fabric is so distorted by differential compaction Hoosier Unit 1-10-3 l-27W3, the cored section that the rock, under manual stress, breaks down into a comprises 6.7 m of white to light grey chert breccia in rubble. At the unconformity with the Cantuar a grey and pale green, sphaerosideritic, kaolinitic Formation, vertical siderite veins, mud-filled fractures, claystone and quartzose siltstone, and an underlying and plant detritus are displayed. In general, as 32.9 m of interbedded brecciated limestone and determined from well cuttings in the district, the limestone breccia in grey green calcareous shale and quartzose sand post-dates the chert and tripolitic facies, quartzose particles. Placement of the formation although locally interbedded with the latter in the boundary between the insolubles of chert and clay, upper one-third of the section. Elsewhere it may concentrated in situ by chemical weathering of the occupy nearly all of the Success section to lie directly Madison limestone, is blurred by joint and cave detrital on, or within a metre or so of, the contact with the fill within the body of the Madison Fonnation. Madison Formation. Whether or not the brecciated limestone of the foregoing section should be considered a dissolution The contour map of the subjacent Mississippian aggregate, i.e. part of the "Residual Zone" or altered erosion surface (Figure 2) displays a southerly tilted 5 1 Figure :Z - Structure map ofthe Mississippian Madi.{OII Formatiofl showing distribution of oil shows i11 the Success, Ctmtuar, Bakke11, a11d Birdbear formatio11s; Kindersley district, so11thwestem Saskatchewan. Contour interval is 40 m; JKs, the erosional edges of the Success; Jgs, Sht1u11avon-Gravelbourg formatioll.{,' Mm, Madison Formt1tio11; the Mann ville 600 m formation water potentiometric co11to11r (downside in direction ofarrows); and perimeter and medians ofSuccess oil shows (---). 34 Summu,y of Investigations I 999. Volume I terrace rimmed by ridges and domes above the -160 m from continental plate motion toward the southwest (msl) contour in the northwest, north, and east, and relative to the mantle. This asymmetry corresponds to overlooking a central depression below -200 m, keeled northeasterly trends of enhanced penneability in some by a westerly-trending trough below -240 m (msl) of the larger oilfields, such as Pembina and Cold Lake along Township 24. A counterpart isopach map of the in Alberta. Success sediments depicts a general th ickening to 79 m in the trough versus a thinning to less than IO m on the The significance of north-south and east-west sets has fl anking and internal highs. In contrast to the northern been under-emphasized in the literature, possibly and eastern rims where the Success sediments end on because of over-print by the northeast-northwest sets. the Mississippian limestone scarps, in the south, The Shaunavon graben in southwestern Saskatchewan between longitudes I 08° and 110°, they are terminated is an example. Its flanks are serrated by elements that on the pediment of the Jurassic-capped Swift Current outline northeasterly oriented terraces and Platform. Southerly extensions of the Success northwesterly troughs, but the graben itself trends sediments onto the platform occur as veneer and valley north from the International Border to latitude 51 °. The fill on the Gravelbourg, Shaunavon, and Rierdon Kindersley structural terrace features a large number of formations in Ranges 29, 27, 26, 25 and 18W3 (e.g. east-west and north-south short lineaments that SaskOil Leader 9- I 5-20-25W3 and SaskO il Speyer 7- probably record a structural history of flexuring 36-2 l-26W3). The erosional cut into the Success between the Swift Current Platform to the south, the Formation, trending east from Kindersley, refl ects pre­ Punnichy Arch to the east, and the Unity structural Cantuar inlay by the Kindersley Paleovalley. Likewise, terrace to the north. Late Jurassic upwarp not only the Success outlier southeast of Rosetown is a survivor focussed westerly pre-Success erosional processes on of pre-Cantuar erosion. the apex of the anti form, and easterly pre-Cantuar siting of the Kindersley Paleovalley, but also facilitated Thus the Success Form ation of the Kindersley district Late Cretaceous salt dissolution collapse structures lies mostly within an upland topographic basin, along extensions of precursor paleovalleys. For excavated from the general mass of the Madison example, an arm of the pre-Cretaceous erosional valley limestone (Figure 2), where the latter flattens in of Township 24 extends eastward into a Late regional dip across the Kindersley region from out of Cretaceous structural depression, as evidenced by a the Williston Basin to the south (Christopher, 1974, comparison of Tidewater Imperial Plato I0-28-25- Figures 17 and 45). The region evidently was arched l 8W3 and Husky Wartime 7-29-25-16W3. Elevation along an east-west axis, karsted, and erosionally of the Madison surface now lies at -229 m (msl) in breached as infilling progressed. The chert-clay detrital both wells, but the former is sited in the erosional suite represents the earlier phase of a depositional trough with 55 m of superjacent Success fill , and the event that includes a penecontemporaneous influx of latter was part of the Cantuar-draped Mississippian kaolinitic quartzose sandstone and siltstone from upland, which at this locality underwent relative outside of the district. Northern outliers of the latter subsidence of at least 55 m. Overall structural relief is facies are encountered in depressions on the sub­ seven times greater than the erosional, as determined Cantuar Devonian erosion surface. by a measure of isopachous differences versus the structural. 3. Structural Elements 4. The Petroliferous Setting Regional and local linears recorded on structure and isopach maps of the Paleozoic and Mesozoic The Kindersley structural terrace, as developed on the formations, and the present topographic surface of Madison erosion surface, is spatially divisible into a