Schlumberger Technology Corporation

Slaheddine Kefi

Jesse Lee

Nikhil Shindgikar

Diankui Fu

Marieliz Garcia-Lopez De Victoria

Trevor Lloyd Hughes

Gary John Tustin

Elena Pershikova

Valerie Lafitte

Olivier Porcherie

Michel Ermel

Mohan Panga

Shiyi Wang

Hafida Achtal

Yamina Boubeguira

Quentin Barral

Chrystel Brunet-Cambus

Mohan K R Panga

Michael J Fuller

Pierre Maroy

Matthew Miller

Bernard Dargaud

Alice Chougnet-Sirapian

Nicolas Droger

Loic Regnault De La Mothe

Andre Garnier

Stephane Boulard

Khooi Tan

Chrystel Cambus-Brunet

Anne-Marie Schulz

Thomas Cochet

Nora Bennani

Dominique Zamora

Well treatment compositions comprise water, a lipophilic anionic surfactant, a hydrophilic non-ionic surfactant, a second non-ionic surfactant, a water-solubilizing solvent, a water-immiscible solvent and a lipophilic non-ionic surfactant. Optionally, a second solvent may be incorporated. When added to spacer fluids, chemical washes or both, the compositions promote the removal of non-aqueous drilling fluids from casing surfaces. Additionally, the treated casing surfaces are water wet, thereby promoting optimal bonding to cement.

Compositions and methods for completing subterranean wells

Method for controlling lost circulation in a subterranean well using oil-dispersible lost-circulation materials which comprise fibers that are coated (or sized) with a lipophilic coupling agent, a lipophilic film-forming polymer or both. The fibers are preferably between about 6 mm and about 25 mm long, and between about 10 &#x3bc;m and about 200 &#x3bc;m in diameter. The fibers may be added to carrier fluids comprising oil-base fluids, synthetic-base fluids, invert-emulsion-base fluids and combinations thereof. The preferred fiber concentration in the carrier fluid is between about 0.55 g/L and about 28.5 g/L. The carrier fluid may be a drilling fluid, a spacer fluid or a lost-circulation pill.

Methods for controlling lost circulation in a subterranean well and materials there for

An apparatus may be used to test the ability of a first fluid to remove a second fluid from a surface. The apparatus comprises a reservoir that contains the first fluid and a testing cell that contains the second fluid. The testing cell also contains a rotor within. The first fluid is pumped into the testing cell, thereby displacing the second fluid. The displaced second fluid flows to a collection vessel. The apparatus is particularly useful for determining the ability of a chemical wash or a spacer fluid to remove non-aqueous drilling fluids from a metallic surface.

Apparatuses and methods for testing wellbore fluids

A process of making observations of a subterranean reservoir penetrated by a wellbore uses distinguishable sets of tracer particles and comprises steps of: The tracer substances are sufficiently distinguishable from each other to enable a tracer substance detected in the produced fluid to identify the set of tracer particles from which it has come and hence identify the location from which it has come. The process may be used in conjunction with hydraulic fracturing, placing sets of particles at different locations within a fracture and/or in different fractures extending from a single wellbore.

Use of encapsulated tracers

A carbohydrate-based compound is used as a setting accelerator in a pumpable geopolymeric suspension for oil and/or gas industry applications. The suspension further comprises an aluminosilicate source, a carrier fluid, and an activator. The suspensions may be placed in a subterranean well and used for well primary cementing operations and/or remedial applications.

Pumpable geopolymers comprising a setting accelerator

The following describes a novel and alternative mechanism in regards to releasing reactive chemicals. Namely, utilizing shells containing multiple emulsions that can be blended with the base fluids, and then react with said base fluid upon exposure to a trigger e.g. high shear and/or elongation flow, therefore plugging even large fractures. Such gelling lost circulation material allows to obtain a reliable carrier and fast reaction when triggered.

Well treatment

Mixtures of fibers and solid particles are effective for curing fluid losses and lost circulation in a subterranean well. Stiff fibers are more effective than flexible ones; however, mixtures of stiff and flexible fibers have a synergistic effect. The quantity and particle-size distribution of the solids are optimized according to the stiffness, dimensions and concentrations of fibers.

Engineered fibers for well treatments

An encapsulated thixotropy agent may be added to aqueous well service fluids. Such fluids include drilling fluids, cement slurries and polymer pills. The well service fluid may be subjected to shearing action downhole, causing the thixotropy agent to be released and imparting thixotropy to the fluid. The thixotropy agent comprises a dry suspension of synthetic layered silicates.

Method for providing thixotrophy to fluids downhole

The invention concerns the use of a fluid loss control additive in a pumpable geopolymeric suspension for oil and/or gas industry applications, said suspension further comprising an aluminosilicate source, a carrier fluid, and an activator, and method of providing such a suspension in a borehole. In particular, the suspension according to the invention is used for well primary cementing operations and/or remedial applications.

Pumpable geopolymers comprising a fluid-loss agent

A process for hydraulic fracturing of a subterranean reservoir formation penetrated by a wellbore includes pumping a fracturing fluid or other aqueous fluid from the surface via the wellbore and into the reservoir. This fluid is an aqueous suspension of particles which each comprise an oilfield chemical distributed within an encapsulating matrix of water-insoluble carrier material. The encapsulating matrix is chosen so as to provide a delayed release of the oilfield chemical from the particles into surrounding fluid, such that oilfield chemical is liberated from the particles after they have entered the fracture. The encapsulating matrix may be a polymer which is at least partially amorphous, with a glass transition temperature below the reservoir temperature.

Use of encapsulated chemical during fracturing

A method is described for treating a subterranean formation with a low viscosity fluid system that contains a viscoelastic surfactant at a concentration too low to viscosify the fluid, but that is concentrated in the formation so that the fluid system gels. The fluid optionally contains a formation-dissolving agent. The fluid is used in matrix acidizing, acid fracturing, and diversion.

Self diverting matrix acid

A method is described for treating a subterranean formation with a low viscosity fluid system that contains a viscoelastic surfactant at a concentration too low to viscosify the fluid, but that is concentrated in the formation so that the fluid system gels. The fluid also contains a formation-dissolving agent. The fluid is used in acidizing, acid fracturing, and diversion.

Method of well cementing with a foamed slurry having a very low water content. When based on ordinary cement, the solid fraction of the slurry includes (by volume) 20-35% Portland cement, 35-65% particles ranging from 200 &#x3bc;m to 600 &#x3bc;m, and 5% to 25% of fine particles in the range 0.5 &#x3bc;m to 5 &#x3bc;m and the water content is less than 50% by volume. When based on micro-cement, the solid fraction includes (by volume) 50-75% micro-cement, 15-40% fine particles in the range 0.5 &#x3bc;m to 5 &#x3bc;m, and 0-20% particles in the rang 3 nanometers to 60 nanometers and the water content is less than 72% by volume.

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Velizy Villacoublay, France

Slaheddine Kefi