Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Timothy L Pope

Yiyan Chen

Jesse Lee

Bruno Lecerf

Philip F Sullivan

Xiaowei Weng

Alejandro Pena

Philippe Enkababian

Hitoshi Onda

Dmitriy Usoltsev

Tarik Itibrout

Dean Michael Willberg

Eric L Hanson

Curtis L Boney

Christopher N Fredd

Dean M Willberg

Golchehreh Salamat

Marina Nikolaevna Bulova

Chad Kraemer

Belgin Baser

Zinaida Usova

Ann M W Hoefer

Abbas Mahdi

Richard Marcinew

Taner Batmaz

Matt Graham

Samuel Cozzens

A system and method for performing stimulation operations at a wellsite having a subterranean formation with of a reservoir therein is provided. The method involves generating a plurality of quality indicators from a plurality of logs, and combining the plurality of quality indicators to form a composite quality indicator. The plurality of stress blocks may then be merged using diversion criterion. The composite quality indicator may be combined with the merged stress blocks to form a combined stress and composite quality indicator, the combined stress and composite quality indicator comprising a plurality of blocks with boundaries therebetween. The method may further comprise defining stages along the combined stress and composite quality indicator based on the diverter-assisted stage classifications; and selectively positioning perforations in select stages based on the diverter-assisted stage classifications thereon.

System and method for performing downhole stimulation operations

A method of treating a subterranean formation comprising generating a fracture in the subterranean formation, introducing a predetermined amount of proppant into a treatment fluid, and subsequently introducing a plugging agent into the treatment fluid before the entire predetermined amount of proppant reaches the fracture, minimizing overdisplacement of the proppant from the fracture.

Methods for minimizing overdisplacement of proppant in fracture treatments

A method of treating a subterranean formation penetrated by a wellbore involves introducing an acid treatment fluid through the wellbore into the formation. The treatment fluid is formed from a zwitterionic viscoelastic surfactant, an acid in an amount to provide the treatment fluid with an initial pH of &#x2266;0 and a rheology enhancer. The treatment fluid has a high viscosity at the initial pH and a lower viscosity when the pH of the treatment fluid is raised to an intermediate pH of from greater than 0 to about 5.

Viscoelastic surfactant acid treatment

An aqueous viscoelastic surfactant (VES) fluid foamed or energized with carbon dioxide, in which the VES is more compatible with the carbon dioxide, is made by the addition of one or more than one synergistic co-surfactant. The synergist co-surfactant includes quaternary amines and ethoxylated carboxylates having a hydrophobic chain shorter than the hydrophobic chain of the VES. Improved compatibility is evidenced for a given surfactant concentration either by formation and maintenance of a foam under conditions at which the foam could not otherwise have been formed or maintained, or by either higher viscosity of the foamed fluid at a given temperature or longer foam life at a given temperature or a higher temperature at which useful fluid viscosity can be generated or maintained for a useful time. The aqueous carbon dioxide foamed fluids may be used in acidizing, acid fracturing, gravel packing, diversion, and well cleanout.

Carbon dioxide foamed fluids

A method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a rheology enhancer selected from partially hydrolyzed polyvinyl ester and partially hydrolyzed polyacrylates. The rheology enhancer also increases fluid viscosity and very low rheology enhancer concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

Viscoelastic surfactant rheology modification

Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

Well treatment with dissolvable polymer

A method for shortening the shear recovery time of zwitterionic viscoelastic surfactant fluids by adding a rheology enhancer having the structure:R-(EO)(PO)&#x2014;R'&#x2014;OHin which R is an alkyl group that is straight chained or branched, saturated or unsaturated, and contains from 3 to about 18 carbon atoms, x is from 0 to about 14, y is from 0 to about 7, R&#x2032; is an alkyl group that contains from 0 to about 14 carbon atoms and is straight chained, branched if having more than 3 carbon atoms, saturated, unsaturated if having more than one carbon atom, the total number of carbon atoms in R plus R&#x2032; is from 3 to about 21, and the EO and PO groups, if present, may be in any order. The rheology enhancer also increases fluid viscosity and thermal stability. Preferred surfactants are betaines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

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Sugar Land, TX, United States of America

Timothy L Pope