Sand control method employing asphaltenes

Abstract

This invention relates to a method for treating wells completed in subterranean formations which contain unconsolidated sand particles, so as to form a permeable barrier which will permit the flow of liquids therethrough while restraining the flow of the unconsolidated sand particles into the well bore. The method comprises saturating sand adjacent the well bore to be treated with petroleum having a high asphaltic content and optionally thereafter contacting the asphaltic petroleum with a solvent capable of solubilizing non-asphaltic fractions of the petroleum and precipitating or causing deposition of the asphaltic or bituminous portions of the petroleum. A heated fluid such as steam is thereafter injected into the formation to cause solidification of the asphaltic materials which effectively binds the sand grains together to form a porous mass which will effectively restrain the movement of sand particles in the well bore upon subsequently placing the well on production. Suitable hydrocarbon materials for causing precipitation of the asphaltic or bituminous portions of the petroleum include liquid paraffinic hydrocarbons such as butane, pentane, or hexane, N-methyl-2-pyrrolidone and furfural. Steam or a mixture of steam and non-condensable gas such as nitrogen, or mixture of steam and air are then injected into the formation to dehydrate and otherwise solidify the precipitated asphaltic material.