Method for constructing high-strength cavity at bottom of vertical well

A construction method and high-strength technology, applied in wellbore/well components, drilling equipment and methods, construction, etc., can solve problems such as unfavorable chamber stability, irregular cavity shape, height, sudden transition, etc., and it is not easy to achieve. The effect of collapsed hole, high formation strength and regular shape

Active Publication Date: 2019-07-16
EXPLORATION TECH RES INST OF CHINESE ACADEMY OF GEOLOGICAL SCI +1
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For drilling in sea areas, due to the softness of the seabed, if you want to obtain a cavity with standard shape, high strength and stability, you must build a pile body whose strength gradually decreases from the center to the periphery. Stability plays a vital role. If the form of reaming cast-in-situ piles is directly used, the strength in the reaming cavity will be high, and the sudden transition to the soft seabed stratum is not conducive to the stability of the chamber; irregular in shape

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
  • Method for constructing high-strength cavity at bottom of vertical well
  • Method for constructing high-strength cavity at bottom of vertical well
  • Method for constructing high-strength cavity at bottom of vertical well

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0025] The construction method of the high-strength chamber at the bottom of the natural gas hydrate vertical well in the sea area of ​​the present invention is a process method carried out by adopting the technology of reaming cast-in-place piles. Two cavities with different diameters are respectively constructed through two chamber expansions. The first The secondary cavity expansion is carried out on the formation below the hydrate floor. The formation is soft, and the jet cavity expansion can be carried out by pumping high-pressure mud into the jet expansion bit. Pump high-strength cement slurry in the jet expansion drill bit for initial pile grouting. Since the perfusion was performed without lifting the drill, the shape and size of the cavity could not be measured, and the requirement of the cavity rule could not be met. Based on the above reasons, it is necessary to carry out secondary cavity expansion on the basis of the high-strength cement primary pile, and pour a pi...

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

PropertyMeasurementUnit
diameteraaaaaaaaaa
depthaaaaaaaaaa
heightaaaaaaaaaa
Login to view more

Abstract

A method for constructing a high-strength cavity at the bottom of a vertical well is used for exploiting natural gas hydrates in sea areas, and comprises the following construction steps that drillinghydrate overlying strata; drilling a stratum below a hydrate bottom plate; expanding a cavity at the stratum under the hydrate bottom plate; pouring high-pressure cement paste without lifting a drillto form a high-strength cement primary pile; drilling the high-strength cement primary pile; secondary cavity expanding; removing slag in the cavity; cavity expanding detection; cementing and filling; and completing the vertical well bottom cavity construction. A reaming cast-in-place pile technology is adopted, by means of two-time cavity expanding and two-time pouring pile forming, the diameterof the primary pile is large, the final pile is subjected to cavity expanding pouring on the basis of the primary pile, the final pile is high in strength and regular in shape, the vertical well bottom cavity is built on the final pile, the stratum strength around the cavity is high, and the requirement on gathering gas production from multiple well groups of horizontal wells to the vertical wellcan be met.

Description

technical field [0001] The invention relates to the technical field of marine natural gas hydrate, in particular to a method for constructing a high-strength chamber at the bottom of a vertical well for natural gas hydrate in the sea. Background technique [0002] Although the test production of natural gas hydrate in the Shenhu area of ​​the South China Sea in 2016 has achieved great success, due to the limitation of the controllable reservoir area of ​​vertical wells, the daily gas production and the continuous stable production time are far from enough, and there is still a long way to go before the industrialization of hydrate production. For long distances, it is an inevitable trend to apply horizontal well drilling technology and multi-well group connection and convergence production technology to the pilot test area for gas hydrate test production. The current global sea area natural gas hydrate test production plan adopts the test production technology of the vertica...

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
Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/01E21B7/12E21B7/28E21B7/18E21B33/13E21B17/00
CPCE21B7/12E21B7/185E21B7/28E21B17/00E21B33/13E21B43/01E21B41/0099
Inventor 宋刚严镔秦绪文胡汉月崔淑英邵玉涛秦如雷陈晓林冯起赠
Owner EXPLORATION TECH RES INST OF CHINESE ACADEMY OF GEOLOGICAL SCI
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