Compound drilling fluid applied to stratums with natural gas hydrates in seafloor

A drilling fluid and hydrate technology, which is applied to drilling compositions, chemical instruments and methods, etc., can solve the problems of reduced fracture pressure, damage of temperature and pressure conditions, easy collapse and fracturing of the well wall, and achieves the formation of hydrates. Inhibition effect increases, reduces and prevents repeated crushing, avoids the effect of serious enlargement of pore size

Inactive Publication Date: 2018-08-03
DALIAN DONGYOU RUIJIA PETROLEUM TECH CO LTD
View PDF3 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] (1) When drilling in natural gas hydrate formations, due to the release of formation stress near the well wall and bottom of the reservoir, the formation pressure will decrease; and the drill bit will cut rock, and the friction between the bottom drilling tool and the well wall and core will generate a large amount of Thermal energy destroys the temperature and pressure conditions for the stable existence of hydrates; thus triggering the decomposition of hydrates, resulting in instability of the well wall and adverse effects on drilling operations
[0004] (2) The invasion of drilling fluid and the decomposition of hydrates will lead to the increase of formation pore pressure in different degrees, and the increase of pore pressure will increase the density of drilling fluid required to maintain the stability of the wellbore wall, which not only seriously affects the penetration rate, but also increases the pressure of the wellbore wall. Seepage increases the pore pressure around the well, ther...

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Compound drilling fluid applied to stratums with natural gas hydrates in seafloor
  • Compound drilling fluid applied to stratums with natural gas hydrates in seafloor
  • Compound drilling fluid applied to stratums with natural gas hydrates in seafloor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Embodiment 1, the content of each component in the drilling fluid is: polyethylene glycol mass ratio is 5%, sodium chloride mass ratio is 14%, ethylene glycol mass ratio is 14%, low viscosity carboxymethyl cellulose LV- The mass ratio of CMC is 1.8%, the mass ratio of potassium polyacrylate is 1.8%, the mass ratio of xanthan gum is 0.4%, the mass ratio of polyvinyl caprolactam is 0.8%, the mass ratio of propylene glycol phenyl ether is 0.8%, and the tetra-n-butyl ammonium phosphate The mass ratio is 0.8%, and the remaining components are water for preparation.

Embodiment 2

[0035] Embodiment two, the contents of each component in the drilling fluid are: polyethylene glycol mass ratio is 6%, sodium chloride mass ratio is 15%, ethylene glycol mass ratio is 15%, low viscosity carboxymethyl cellulose LV- The mass ratio of CMC is 2%, the mass ratio of potassium polyacrylate is 2%, the mass ratio of xanthan gum is 0.5%, the mass ratio of polyvinyl caprolactam is 1%, the mass ratio of propylene glycol phenyl ether is 1%, tetra-n-butyl ammonium phosphate The mass ratio is 1%, and the remaining components are water for preparation.

Embodiment 3

[0036] Embodiment three, the contents of each component in the drilling fluid are: polyethylene glycol mass ratio is 7%, sodium chloride mass ratio is 16%, ethylene glycol mass ratio is 16%, low viscosity carboxymethyl cellulose LV- The mass ratio of CMC is 2.2%, the mass ratio of potassium polyacrylate is 2.2%, the mass ratio of xanthan gum is 0.6%, the mass ratio of polyvinyl caprolactam is 1.2%, the mass ratio of propylene glycol phenyl ether is 1.2%, and the tetra-n-butyl ammonium phosphate The mass ratio is 1.2%, and the rest is water for preparation.

[0037] The drilling fluid configuration methods of the above-mentioned examples 1, 2, and 3 are conventional drilling fluid configuration methods, and are evaluated by the following experimental methods:

[0038] 1 Evaluation of drilling fluid shale hydration inhibition

[0039] Inhibition evaluation experiment is an important part of the indoor evaluation of drilling fluid related performance. The present invention adopt...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides compound drilling fluid applied to stratums with natural gas hydrates in the seafloor and relates to the field of exploitation of natural gas hydrates. The drilling fluid comprises the following components: polyethylene glycol, sodium chloride, ethylene glycol, low-viscosity carboxymethyl cellulose LV-CMC, potassium polyacrylate, xanthan gum, polyvinyl caprolactam, propyleneglycol phenyl ether, tetranbutylammonium phosphate and prepared water. The compound drilling fluid is capable of being applied to drilling with storage of the natural gas hydrates in the seafloor, isfree of solid phase and has resistance to low temperature; kinetic inhibitors and synergists are added into the drilling fluid and are compounded with each other; the drilling fluid has a relativelystrong effect of inhibiting generation of the hydrates; meanwhile, the components of the drilling fluid are low in harm to environment; and the drilling fluid has the advantages of high efficiency, environment friendliness and cheap and easily available raw materials.

Description

technical field [0001] The invention relates to a compound drilling fluid for subsea natural gas hydrate formation, in particular to the field of natural gas hydrate exploitation. Background technique [0002] Natural gas hydrates are mainly distributed in the deep-water areas of the continental margins and the permafrost areas on land, and the former accounts for the vast majority of the discovered quantities. Natural gas hydrate is one of the potential alternative energy sources, and the research on natural gas hydrate is a hot spot in contemporary earth science and energy industry development research. There are a large amount of natural gas hydrates in seabed sediments. Drilling is an essential means to explore and develop natural gas hydrates at a certain depth underground. The phase equilibrium property of gas hydrate determines that drilling in this type of formation is very different from drilling in general oil and gas formations, and it also leads to more complex ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C09K8/12
CPCC09K8/12C09K2208/12C09K2208/22
Inventor 李海洋龚鑫晶张晓丽袁鹏飞李新
Owner DALIAN DONGYOU RUIJIA PETROLEUM TECH CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap