Characterization of Surface Energies of Hydrocarbon Formation Rocks for Enhanced Hydrocarbon Recovery
Quoc P. Nguyen, Gary A. Pope
Funding source: Saudi Aramco
Funding amount: $250,000 per year
The physical and chemical interactions between crudes, brines, and rock determine both oil reserves and producibility. Measurements of these interactions are difficult and research in the past has mainly concentrated on sandstone reservoirs. In particular, limestones and dolomites are poorly investigated.
Yet these inter-molecular forces govern the transport of formation fluids. Lifshitz-van der Waals (LW) theory allows estimating the contribution of LW interactions to solid and liquid surface free energies. However, the LW interactions do not sufficiently account for the high surface and interfacial free energies of several substances. Nearly all of the chemical reactions between liquids and solids surfaces that are important in forming interfaces are Lewis acid-base (AB) reactions. Both LW and AB interaction strengths of a rock surface can be accurately determined by inverse gas chromatography. Understanding of surface and interfacial properties of fluids (i.e., formation brines, crude oils, etc.) and rocks is the key to the success of wettability alteration and interfacial tension reduction as the most effective approaches for mitigating formation damage and mobilizing oil.