INTRODUCTION
The Mississippian rocks of Kansas are regarded as the largest oil producing unit in the Midcontinent. These rocks have produced oil both at the top and within the sequence unit. The name “Chat” is given to these rocks because their high porosity and low resistivity characteristics (Rogers, 2001). Over 6000 well-logs such as neutron, density and resistivity have been studied in Kansas and result shows that the chat is everywhere but lack uniformity. Depositional and diagenetic process such as dissolution have hindered the accessibility of the chat reservoir.
To understand the characteristics of the Mississippian chat, it is important to understand the diagenesis, depositional environment, and it petrophysical characteristics (Rogers, 2001). Four types of formation are present in the Mississippian age namely Kinderhookian, Osagian, …show more content…
Well log analysis is expected to support these parameters such as density/neutron log porosity indicating a porosity value between 15% and 35% for oil production, low resistivity value between 1ohmm and 2ohmm. (Watney et al, 2001). The micro-inverse and micro-normal logs will show a separation to indicate zones that are permeable.
Vuggy, moldic and intragranular porosities resulting from diagenetic process should be observed in core. Three types of lithofacies are expected to be found in the core; argillaceous dolomite mudstone, nodular to bedded chert, and bioclastic crinoidal wackestone to grainstone. Lithologic characteristics associated with the Mississippian rocks include fine grain sizes, large pores, abundance of marine fossils, horizontal bedding and few organic burrow structures. These properties suggest the depositional environment of the lithofacies. Previous studies described the Mississippian rocks of Kansas to be deposited in shallow marine
The Mississippian rocks of Kansas are regarded as the largest oil producing unit in the Midcontinent. These rocks have produced oil both at the top and within the sequence unit. The name “Chat” is given to these rocks because their high porosity and low resistivity characteristics (Rogers, 2001). Over 6000 well-logs such as neutron, density and resistivity have been studied in Kansas and result shows that the chat is everywhere but lack uniformity. Depositional and diagenetic process such as dissolution have hindered the accessibility of the chat reservoir.
To understand the characteristics of the Mississippian chat, it is important to understand the diagenesis, depositional environment, and it petrophysical characteristics (Rogers, 2001). Four types of formation are present in the Mississippian age namely Kinderhookian, Osagian, …show more content…
Well log analysis is expected to support these parameters such as density/neutron log porosity indicating a porosity value between 15% and 35% for oil production, low resistivity value between 1ohmm and 2ohmm. (Watney et al, 2001). The micro-inverse and micro-normal logs will show a separation to indicate zones that are permeable.
Vuggy, moldic and intragranular porosities resulting from diagenetic process should be observed in core. Three types of lithofacies are expected to be found in the core; argillaceous dolomite mudstone, nodular to bedded chert, and bioclastic crinoidal wackestone to grainstone. Lithologic characteristics associated with the Mississippian rocks include fine grain sizes, large pores, abundance of marine fossils, horizontal bedding and few organic burrow structures. These properties suggest the depositional environment of the lithofacies. Previous studies described the Mississippian rocks of Kansas to be deposited in shallow marine