Pyrobitumen Induced Formation Damage Problems

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 acidstimulatio, was examined using coreflood experiments. Electrophoretic mobility measurments and surfacant adsorption coreflood experiements were performed to study the effects of pyrobitumen on the surface propeties and adsorption behaviour of these carbonat rocks. The effect of pyrobitumen on the wettability of carbonate rocks was investigated in the contact angle experiments. Introduction Objectives and Scope Pyrobitumen, a solid, black, bituminous material, has been observed insignificant quanities worldwide, especially in Albetra Devonian carbonates. Thesolid hydrocarbons are present in the carbonate rock as either pore-filling orpoe-lining material within the vugular and the intercrystalline pore network. Although pyrobitumen has been observed in Alberta carbonate reservoirs, very little is known about its effect on some basic rock properties such as porosity, permeability, and wettability. All of these properties may have a significant influence on hydrocarbon recovery processes.