A nanocomposite toughened oil well cement and its preparation method and application

Abstract

The invention discloses nano composite toughened oil well cement and a preparation method and application thereof. The nano composite toughened oil well cement is characterized by being prepared from,by weight, 100 parts of cement, 0.5-5 parts of self-assembled carbon nanotube / nano carbon black, 0.1-1.0 part of a dispersing agent, 0.2-0.9 part of a retarder, 0-2 parts of a fluid loss agent, 0-0.5part of an antifoaming agent and 40-60 parts of water. The self-assembled carbon nanotube / nano carbon black is prepared from an electrostatic self-assembly process and is in a grape bunch structure.Under low doping of self-assembled carbon nanotube / nano carbon black, oil well cement slurry which is high in stability, free of sedimentation, high in rheological property, adjustable in thickening time and low in water loss can be prepared according to a traditional process, hardened oil well set cement has excellent characteristics including low elasticity modulus and high ultimate compressivestrength, the problem that an oil well cement sheath is prone to cracking in a unconventional complex load environment can be solved, long-term cementing integrality in well cementation is guaranteed,the service life of an oil-gas well is prolonged, and the recovery ratio is increased.

Description

technical field [0001] The invention relates to a nanocomposite toughened oil well cement and its preparation method and application, belonging to the fields of low brittleness, high toughness and high strength oil well cement material preparation and oil and gas exploration and development. Background technique [0002] Oil well cement stones need to withstand complex environmental conditions such as temperature, pressure, drilling, injection and production, etc., which are prone to cracks and annulus, destroying the integrity of cement stones, and seriously affecting the productivity, production life and safety of oil and gas wells. In the harsh unconventional oil and gas extraction environment, the cement should have higher strength and lower elastic modulus, which will help ensure that it can resist various complex environmental loads without damage during its life cycle. The oil well cement toughening materials used in existing research mainly include fiber materials, o...

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Problems solved by technology

[0003] In order to solve the above problems, the object of the present invention is to provide a nanocomposite toughened oil well cement and its preparation method and application, which uses electrostatic self-assembled carbon nanotubes / nano carbon black for toughening and strengthening modification of oil well cement, which can Solve the dispersion problem of conventional nano-toughening materials in oil well cement, overcome the weak area produced by organic latex toughening materials in hardened cement stone, solve the problem of agglomeration of traditional fiber toughening materials, and use traditional technology to prepare oil well cement The slurry has good stability, no settlement phenomenon, good rheology, adjustable thickening time, small water loss, low elastic modulus, high ultimate compressive strength, and can solve the problem of oil well cement sheath under unconventional complex load environment. Cracking problem, ensuring the long-term sealing integrity of cementing, prolonging the life of oil and gas wells, and improving recovery

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