High performance clay swelling inhibitors play a vital role in improving inhibition characteristics of shales. The linkages between the inhibition's characteristics of the non-ionic surfactant extract from bio-based inhibitors are yet to be fully explored in the literature. This paper reports the use of a crude extract containing saponins from Chromolaena odorata (CO) leaf, which act as surfactants for inhibiting shale hydration. Determination of the inhibitive property of nonionic surfactant was made through measurements of surface-active properties, inhibition tests, filtration, rheological and strength test. The experimental findings on CO showed that it was highly compatible and very stable with conventional water-based drilling fluids (WBDFs), a highly effective shale inhibitor and a works through plugging and viscosity acting effect in the shale system.

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The focal point of this project is to investigate and assess the potentiality of an enhanced waterflooding process by a naturally generated surfactant (Protein-Enzyme bio-surfactant). The effect of low salinity (LSW), and LSW combined with a bio-surfactant (Protein-Enzyme) in a tertiary mode flooding comparatively. A high salinity water (HS) (0.75 M) was used to flood in the secondary mode after aging the crude saturated core with an initial water saturation of 19%, a recovery of 68.15% oil initially in place (OIIP) was recovered until no further recovery. Upon flooding with a LSW (90% dilution of HS), a further incremental recovery of 11.1% OIIP was produced. Enhancing the LSW with bio-surfactant in a third flooding sequence, an additional 3.75% OIIP was recovered. Analysing the mechanism of LSW bio-surfactant with fractional flow, a high recovery of 0.583 PV (pore volumes) at breakthrough was estimated. Thus, an alteration in ionic strength (salinity) by a 90% dilution and combination of bio-surfactant, saw an incremental recovery, which indicates the potential of LSW bio-surfactant on recovery of residual oil saturation.

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A post-drill pore pressure and fracture gradient analyses were conducted on a field in the Tano Basin of Ghana with the primary objective of predicting as accurately as possible the pore pressure, fracture pressure and the overburden pressure from the well logs data of two wells. The wells were drilled offshore in water depths of about 95.4 m and 124.4 m. Eaton's method coupled with depth-dependent Normal Compaction Trendlines (NCT) and Mathews and Kelly method were used in determining the pore pressure and fracture gradient. The results indicate that average pore pressure gradient, fracture pressure gradient and overburden pressure gradient for the first well are 1.423 psi/m (8.34ppg), 3.514psi/m (20.6ppg) and 4.299psi/m (25.2ppg) respectively whiles values for the second well are 1.423psi/m (8.34ppg), 3.85psi/m (21ppg) and 4.299psi/m (25.2ppg) respectively. These values were predicted to be required to maintain the stability of the wells using accurate mud weight.