Schlumberger Technology Corporation

Shiyi Wang

Gary John Tustin

Trevor Lloyd Hughes

Valerie Lafitte

Slaheddine Kefi

Carlos Abad

Diankui Fu

Bruno Lecerf

Alexander Nadeev

Matthew Miller

Alexander Martin Wilson

Andrey Vladimirovich Fedorov

Vadim Kamilievich Khlestkin

Olesya Levanyuk

Khooi Tan

Tatiana Zolnikova

Thomas Cochet

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 method for treating a subterranean formation penetrated by a wellbore is provided. The method includes providing a treatment fluid containing a viscoelastic surfactant having at least one degradable linkage, a hydrolysable material, and a pH control material, and injecting the treatment fluid into a subterranean formation. The pH control material may have a pH equal or greater than about 9 and may include a strongly alkaline material and an oxidizing agent.

Method for treating subterranean formation with degradable material

The magnitude of asphaltic precipitation when injecting a viscosity reducing diluent into a reservoir formation, notably to assist oil recovery therefrom, is forecast by (i) determining a relationship between asphaltic precipitation and a solubility parameter for the diluted oil, and then (ii) utilizing that relationship to forecast the magnitude of asphaltic precipitation when injecting a predetermined viscosity reducing diluent into the formation. Making this forecast may be followed by injecting a viscosity reducing diluent into the formation to assist oil recovery. The diluent may in particular be supercritical carbon dioxide or other asphaltene precipitant mixed with a more polar material in proportions designed by forecasting asphaltic precipitation by candidate materials in possible proportions.

Forecasting asphaltic precipitation

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

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Cambridge, United Kingdom

Shiyi Wang