Fractured Smackover Limestone in Northeast Louisiana; Implications for Hydrocarbon Exploitation

Abstract

ABSTRACT Highly fractured Jurassic Smackover carbonates are present in northeast Louisiana in an area covering more than 2,000 sq mi (5,120 sq km). Vertically, more than 1,000 feet (330 m) of fractured section has been recovered in continuous conventional cores through the Smackover Formation. The most extensively fractured section extends eastward from Union and Ouachita Parishes in Louisiana into west central Mississippi, and northward from the northern part of Richland and Madison Parishes into southeast Arkansas. Wrench faulting together with normal faulting are likely causes of the shear and extension fractures found in the Smackover. The intensity of the fracturing appears to be extremely high when compared to the level observed elsewhere in the Gulf Coast Basin's productive Smackover trend. Regionally, wrench faulting and its related fracturing also may have provided a process for generating vertical and long distance hydrocarbon migration pathways from Middle and Lower Smackover source beds. These source rocks combined with: 1) a subsequent favorable thermal history, 2) an overlying upper Smackover reservoir (developed by depositional, secondary and structural processes), and 3) an effective overlying seal, have yielded a favorable hydrocarbon system. The fractured Smackover has been sparsely drilled and currently the area has no production from these rocks.