Analysis of Joints Patterns in Albian to Santonian Strata on the Eastern Flank of the Abakaliki Anticlinorium: Implications on Paleostress Conditions and Fluid Flow Properties in an Unconventional Petroleum System

An analysis of joint patterns were carried out on multiple exposures in Albian to Turonian strata belonging the Abakaliki Formation (Asu River Group) and Eze-Aku (Eze-Aku eastern flank Anticlinorium Southern Benue Trough. The was using FracPaQ a MATLAB based toolbox for quantification fracture patterns. tool used calculate density, intensity traces; quantify scaling distributions, determine dilation tendencies, slip connectivity, fluid flow directions. Analysis show presence two major systems: A Major Cross-Fold Joint (CF-J) system -orthogonal regional fold axes- consisting CF-J1 set trending NW/SE (315±5°), subordinate Longitudinal System (L-J) -subparallel NE-SW L-j1 set, an ENE-WSW (60°±5°) L-j2 E-W L-j3 set. Fracture density ranging from 11.2395- 53.3443 m-1 85.2747- 629.5928 m-2 respectively. Joints high low tendencies given NW-SE directed maximum principal horizontal stress σH field. units better connectivity lower permeability anisotropy as both systems are well developed those units. These joints, having formed period leading up Santonian inversion would have been ideal conduits migration hydrocarbon mineral fluids. precedes folding episode is likely result overpressure conditions due disequilibrium compaction Albian- initial compressive tectonic later related outer-arc flexure folded taking advantage nascent cleavage structures shale