Abstract
Pyrobitumen is a black solid insoluble carboniferous deposit derived from thermal degradation of hydrocarbons. Although the organic material has been observed in carbonate rocks world-wide, very little is known about its effect on some basic rock properties such as porosity, permeability, wettability, and potential for formation damage. All of these properties play significant roles in hydrocarbon recovery processes.
In this study, the amount and distribution of pyrobitumen were determined using a newly developed ashing method. Potential formation damage, which can be caused by entrainment of pyrobitumen during waterflood, oil production and acid stimulation, was examined using coreflood experiments. Electrophoretic mobility measurements and surfactant adsorption coreflood experiments were performed to study the effects of pyrobitumen on the surface properties and adsorption behaviour of these carbonate rocks. The effect of pyrobitumen on the wettability of carbonate rocks was investigated in the contact angle experiments.
