Abstract: Gravel pack composition containing gravel and a water-in-oil emulsion including (a) an organic continuous phase comprising 0.1 to 5 vol % of the emulsion of non-ionic or cationic surfactant and 0.25 to 3 vol % of the emulsion of sorbitan ester; (b) a dispersed aqueous phase comprising 0.05 to 3 vol % of the emulsion of a partial ester of a polyol with at least one C6 to C22 fatty acid and at least one of an acid, acid precursor, and a chelating agent; and (c) a density control agent. The fluid can display a delayed break of up to about 72 hours to enable clean-up of mud cake.

Abstract: Method of treating a subterranean hydrocarbon-bearing formation comprising unconsolidated or poorly consolidated particulates, by contacting the formation with a solution or a dispersion of an organosilane which is a silylated polymer of formula (I): (RO)3-nRnSi-A-B-A-Si(OR)3-nRns??(I) wherein each R is independently a substituted or unsubstituted, alkyl group having from 1 to 6 carbon atoms, or a —C(O)R group where R is as hereinbefore defined; n is 0, 1 or 2; each A is a divalent organic radical; and B is a poly(oxyalkylene) linking group, a polyurethane linking group, or a poly(meth)acrylate linking group wherein the poly(oxyalkylene) linking group or the polyurethane linking group has a number average molar mass in the range of 600 to 20,000 g mol?1. The poly(meth)acrylate linking group has a number average molar mass in the range of 600 to 40,000 g mol?1.

Abstract: A method of strengthening subterranean formation by drilling and completing a wellbore penetrating at least one unconsolidated or weakly consolidated formation, the method comprising: (a) drilling at least one interval of the wellbore that penetrates the unconsolidated or weakly consolidated formation using a drilling mud comprising a base fluid comprising an aqueous phase containing up to 25% weight by volume (% w/v) of a water soluble silicate, wherein the drilling mud has an acid-soluble particulate bridging solid suspended therein that is formed from a salt of a multivalent cation, wherein the salt of the multivalent cation is capable of providing dissolved multivalent cations when in the presence of an acid; (b) subsequently introducing a breaker fluid containing an acid and/or an acid precursor into the wellbore; (c) allowing the breaker fluid to soak in the interval that penetrates the unconsolidated or weakly consolidated formation for a predetermined period and strengthening formation by reacting wit

Abstract: A gravel pack composition comprising i) a water-in-oil emulsion comprising: a) an organic continuous phase comprising 0.1 to 5 vol % of the emulsion of non-ionic or cationic surfactant and 0.25 to 3 vol % of the emulsion of sorbitan ester; b) a dispersed aqueous phase comprising 0.05 to 3 vol % of the emulsion of a partial ester of a polyol with at least one C6 to C22 fatty acid and at least one of an acid, acid precursor, and a chelating agent; and c) a density control agent; and ii) gravel. The fluid can display a delayed break of up to about 72 hours to enable clean-up of mud cake.

Abstract: A method of treating a subterranean hydrocarbon-bearing formation comprising unconsolidated or poorly consolidated particulates, the method comprising contacting the formation with a solution or a dispersion of an organosilane, characterised in that the organosilane is a silylated polymer of formula (I): (RO)3-nRnSi-A-B-A-Si(OR)3-nRn (I) wherein each R is independently a substituted or unsubstituted, preferably unsubstituted, alkyl group having from 1 to 6 carbon atoms, preferably, 1 to 3 carbon atoms, or a —C(O)R group where R is as hereinbefore defined; n is 0, 1 or 2; each A is a divalent organic radical, for example, an alkoxy linking group such as propoxy; and B is a poly(oxyalkylene) linking group, a polyurethane linking group, or a poly(meth)acrylate linking group wherein the poly(oxyalkylene) linking group or the polyurethane linking group has a number average molar mass in the range of 600 to 20,000 g mol?1 and the poly(meth)acrylate linking group has a number average molar mass in the range of 600 t