Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Retardation cement mortar

A cement slurry and retarding technology, applied in the field of retarded cement slurry, can solve the problems of cement slurry wellbore sealing, oil pipes and downhole tools not being pulled out, etc.

Active Publication Date: 2011-08-31
中国石油化工股份有限公司河南油田分公司石油工程技术研究院 +1
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a retarded cement slurry with a long retarding time, so as to solve the problem of cement slurry in construction operations such as water plugging, sand prevention and sealing of heavy oil thermal recovery wells, profile control of water injection wells, and plugging of coal seams. The existing wellbore is sealed, and the tubing and downhole tools cannot be pulled out.

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0010] The retarded cement slurry of the present invention is prepared from the following components in weight percent: urea: 23.4%, guar gum: 0.05%, G grade cement: 53%, water: 23.55%. The guar gum in this implementation is the suspending agent.

[0011] Thickening time at 40°C > 48 hours (initial consistency 2.6Bc, after 48 hours the consistency is 0.8Bc); put it into the mold and wait for 3 days to take it out, the compressive strength is 12.4MPa.

Embodiment 2

[0013] The retarded cement slurry of the present invention is prepared from the following components in weight percent: urea: 21.2%, guar gum: 0.05%, G grade cement: 57.7%, water: 21.05%.

[0014] Thickening time at 40°C > 18 hours (initial consistency 3.3Bc, after 18 hours the consistency is 6.2Bc); put it into the mold and wait for 3 days to take it out, the compressive strength is 15.4MPa.

Embodiment 3

[0016] The retarded cement slurry of the present invention is prepared from the following components in weight percent: urea: 19.2%, guar gum: 0.1%, G-grade cement: 61.4%, and water 19.3%.

[0017] Thickening time at 40°C > 10 hours (initial consistency 3.6Bc, 8.8Bc after 10 hours); put it into the mold and wait for 3 days to take it out, the compressive strength is 17.5MPa.

[0018] During on-site construction, add water, urea, and suspending agent to the mixing tank according to the formula, stir until dissolved, then add cement in a metered amount, continue to stir evenly, and use a squeeze pump or cement truck to pump in the front liquid and retarded cement accordingly Slurry, displacement fluid, subsequent backwashing of the well, adoption of steam injection to accelerate coagulation, or shutting down the formation to automatically raise the temperature and wait for coagulation can be determined according to specific conditions.

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
compressive strengthaaaaaaaaaa
thermal resistanceaaaaaaaaaa
Login to View More

Abstract

The invention discloses retarded cement slurry. The retarded cement slurry comprises the following components in percentage by weight: 15 to 35 percent of urea, 0.01 to 0.1 percent of suspending agent, 30 to 65 percent of cement, and 19 to 35 percent of water. In the components of the cement slurry, the urea has the following functions: (1) the urea changes the nature of pure water as the urea molecules and water molecules form hydrogen bonds; and (2) the existence of the urea in the water reduces the chance of the contact between cement particles and water molecules which both have the function of settling retardation. The function of the suspending agent in the retarded cement slurry is to reduce the sedimentation and aggregation speed of the cement in the water for convenient inject via a pump. The retarded cement slurry can make the thickening time of the G-grade cement slurry at 40 DEG C reach 10 to 48 hours. The main technical indexes of the retarded cement slurry are as follows: the thickening time at 40 DEG C is between 10 and 48 hours; the compressive strength after solidification is between 4 and 27MPa; and the temperature resistance after solidification is more than or equal to 300 DEG C.

Description

technical field [0001] The invention relates to a slow-setting cement slurry, in particular to a slow-setting cement slurry used for water shutoff of oil wells, profile control of water injection wells, sand prevention and sealing of heavy oil thermal recovery wells, etc., and belongs to the field of chemical water shutoff and profile control of oil fields. Background technique [0002] At present, the cement slurry used in domestic and foreign oilfield oil wells for water plugging and sand consolidation, heavy oil thermal recovery wells for sand control, channel sealing, oilfield water injection well profile control, and coal seam permeation plugging generally has the disadvantage of fast thickening. Less than 2 hours (the thickening time of G-grade cement slurry with a water-cement ratio of 0.44 is about 90 minutes at 40°C), while using cement slurry for water plugging and sand consolidation in oil wells, sand control and channel sealing in heavy oil thermal recovery wells,...

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 Patents(China)
IPC IPC(8): C04B28/00C04B24/12
Inventor 路群祥张文玉姚奕明贾丽云黄春燕
Owner 中国石油化工股份有限公司河南油田分公司石油工程技术研究院
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products