Shell Oil Comapny

Halliburton Energy Services, Inc.

Baroid Technology, Inc.

Jimmie B Lawson

David R Thigpen

Robert J Faircloth

Gerald C Adams

Richard Louis Nelson

Edwin A Richardson

Donald Lee Whitfill

George Neal Iken

Bradley Leon Todd

Lee Nicky Morgenthaler

Joseph Reisberg

Randolph H Knapp

David C Berkshire

Andrew H Falls

Harold J Hill

George J Hirasaki

Webster M Sawyer, Jr

Jeffery G Southwick

Robert Farmer, Iii

A system and method for removing particles from a well bore penetrating a possible hydrocarbon producing formation, according to which drilling fluid is mixed with a weighted material, and the mixture is introduced into a well bore so that the mixture scours any particles accumulated in the well bore. A well-completion fluid is introduced into the well bore that dissolves the weighted material.

System and method for removing particles from a well bore penetrating a possible producing formation

Drilling fluids are designed for drilling and cementing through shallow water flows and unconsolidated formations. Such drilling fluids utilize hollow microspheres to increase the volume of the drilling fluid without adding too much weight to the drilling fluid. The drilling fluid is also designed to employ an admixture of silicate, high surface area fibrous material, deformable graphite particles, and an activatable cementitious material to stabilize unconsolidated formations and form a tough filter cake that will bond with the cement casing.

Drilling and cementing through shallow waterflows

A scale inhibitor solution composition comprising water; an organophosphorous scale inhibitor selected from the group consisting of nitrilotri(methylene phosphonic acid), diethylenetriaminepenta-(methylene phosphonic acid) and salts thereof with monovalent cations; and sodium chloride in a concentration of between about 12 and about 14% by weight of the scale inhibitor solution.

Precipitation of scale inhibitors

A method is provided to fracture a subterranean formation along with a fracturing fluid useful in this method, the method comprising the steps of: a) providing a fracturing fluid, the fracturing fluid is an aqueous solution having an initial pH greater than about 8 and comprising a polysaccharide, a source of borate in an amount that is effective to crosslink the polysaccharide at a pH greater than 8, an oxidative breaker, and a precursor that hydrolyzes in an amount that is effective to lower the pH of the fracturing fluid after a time period that is greater than about one half hour and less than about two days; b) injecting the fracturing fluid into the formation at a pressure the is effective to fracture the formation and force at least a portion of the fracturing fluid into the fracture; and c) permitting the precursor to hydrolyze and thereby lowering the pH of the fracturing fluid to a pH that is less than about 8.

Formation fracturing

The present invention is a method to improve permeability of a formation in the vicinity of a production wellbore. An acid treatment composition is placed in the formation after a foaming composition is injected and a foam created from the foaming composition, thus forcing the acid treatment composition into less permeable strata. The foaming composition contains a sulfate surfactant as a foam stabilization agent. The sulfate hydrolyzes after a time period that is long enough to permit placement of the acid treatment composition. After the sulfate hydrolyzes, it becomes ineffective as a surfactant. Fluids produced from the formation after the acid treatment according to the present invention therefore do not contain significant concentrations of active surfactants, and therefore do not create foams or emulsions in surface separation equipment.

Acid stimulation process for production from subterranean formations

A method to place anionic scale inhibitors in formations containing CaSO.sub.4 is provided. The solution dissolves CaSO.sub.4 when injected into the formation containing CaSO.sub.4 causing calcium salts of the scale inhibitor to precipitate at a rate and to an extent that exceeds that resulting when an inhibitor solution not containing the salt is used. Precipitation of the calcium salt of scale inhibitor is maximized because salt reduces its solubility.

Scale inhibitors are precipitated in a formation by injection in an acidic solution comprising a base generating component and a chelating agent. The inhibitor is preferably a calcium salt of an organic phosphonate. The chelating agent prevents iron ions from causing premature hydrolysis of the base generating component.

Precipitation of scale inhibitors in subterranean formations

Calcium silicate filter aids have been found to be effective to remove colloidal iron suspensions from aqueous streams without plugging filters. Calcium silicate filter aid is made by heating diatomaceous earth with hydrous lime.

Iron hydroxide removal method

Scale inhibitors are precipitated in a formation by injection in an acidic solution comprising a base generating component. The inhibitor is preferably a calcium salt of an organic phosphonate.

An aqueous alkaline flood for recovering oil from a reservoir containing acidic oil is improved by adding to the injected aqueous alkaline solution both a stoichiometric excess of the alkaline material and a kind and amount of preformed cosurfactant material that increases the salinity of that solution so that, in contact with the oil in the reservoir, it will form a surfactant system having a salinity requirement which minimizes the interfacial tension between it and the oil.

Preformed surfactant-optimized aqueous alkaline flood

An aqueous alkaline oil recovery fluid containing monovalent salt, and, optionally, preformed cosurfactant, is improved by using a mixture of alkaline silicate and carbonate salts in specified proportions as the alkaline material.

Preparing an aqueous alkaline solution for recovery of oil from a

In a process for injecting a steam-foam-forming mixture into a subterranean reservoir to displace oil, injecting a mixture containing only as much noncondensible gas as required for substantially reducing the mobility of an injected steam-foam-forming mixture containing a given kind and amount of surfactant and electrolyte, which amount of noncondensible gas to add is calculated from a specified equation interrelating the reservoir temperature and pore size.

Process for optimizing the noncondensible gas content of an

Oil is recovered from an acidic oil reservoir by injecting an alkaline, saline, aqueous solution containing proportions of preformed cosurfactant which are decreased as increasing amounts of the solution are injected.

Staged preformed-surfactant-optimized aqueous alkaline flood

The scaling of a production well in a clay-containing reservoir is inhibited by injecting a scale inhibitor dissolved in an aqueous solution having a pH and ratio of monovalent-to-multivalent cations such that multivalent cation salts of the inhibitor are precipitated as a result of a cation-exchange within the reservoir.

Treating wells with ion-exchange-precipitated scale inhibitor

The scaling of a producing well is inhibited by injecting a self-reacting alkaline aqueous solution of a pH-lowering reactant, a compound containing scale-inhibiting anions and a compound containing multivalent cations, which solution subsequently precipitates a slightly soluble scale inhibitor within the reservoir.

Growing community of inventors

Houston, TX, United States of America

Jimmie B Lawson