RRJ#3

EPA 1 Core

Reference: Geology Articles (2008, April) “Assessment of Undiscovered Oil Resources in the Devonian-Mississippian Bakken Shale Formation, Williston Basin Province, Montana and North Dakota”, 2008. Retrieved on February 17, 2009, from http://geology.com/usgs/bakken-formation-oil.shtml

Name: Artur Canumbila

Summary:
Geology’s article, entitled “Assessment of Undiscovered Oil Resources in the Devonian-Mississippian Bakken Shale Formation, Williston Basin Province, Montana and North Dakota” processes the study made on the Bakken shale Formation in areas of the Montana, Canada and North Dakota about the possible prospectivity of hydrocarbon in this area. They evaluated the area through the many geology subjects,such as total petroleum systems that involved source rock distribution, thickness, organic richness, maturation, petroleum generation and migration, reservoir rock, distribution and quality, trap, timing also stratigraphic studies, structural geology, geochemistry associated in historical exploration and production results and interpretations. They found that the Bakken Shale Formation is composed of three layers where upper and lower layers is lithologically composed of shale rich in organic matter, moderately uniform, and the middle layer composed of sandstone with a very good petrophysical characteristic. The two layers of shale are source rock and sandstone is the reservoir. The two figures on the first page illustrate a limitation of the possible prospect or lead, and the figure below shows how the rate of productivity of the hydrocarbon was during 6 years, also, it illustrates the increment of productivity which demonstrates how good the reservoir behavior through the time is. On figure one of page 2 it shows the limitation of oil generation and main structures, and figure 2 below shows oil generation area, five blocks uniforms of appraisal, the area defined as not discovered yet in Bakken Formation, and limitation of oil generation in the upper part same the some Formation. Finally, the study shows the result of the reserve’s estimation of the Bekken Formation .

Reaction:
I agree with their study, in the way that they used the subjects and data mentioned in order to get valuable interpretation for prospect assessment; however, uncertainties always exist before drilling the hole. This study seems to be fascinating, but at same time has a lack of consistency and coherency in its interpretation.. First, Bakken formation is thin, but covers large area, and the two shale units are fairly consistent (2 paragraph).This tells me that even if the Bakken Formation generates hydrocarbon the could be uneconomic due to the volumetry and quantity. Second, on figure 2 it shows the limitation of the area of oil generation for the upper shale layer of the formation; therefore, oil generation is entirely related with depth, geothermal gradient, maturity and type of source rock, so there is a probability that the lower shale generates gas, water or nothing. Nevertheless, the study illustrate some advantages related to the reservoir sandstone which increases productivity through time without depletion, but it can not guarantee the presence of a good petrographic characteristic all over the area, because we have to take into account the drastic local litholigic change. The assessment project still is incognita but slightly promissory. We need more data, more work for making Bakken formation estimation prospective because this estimation still is unrealistic.