Extended slurry
Technical field
The present invention relates to a kind of extended slurry, relate in particular to a kind of extended slurry that the anti-sand seal of oilwell water shutoff, water injection well profile control, thick oil thermal extraction such as scurries at the aspect that is used for, belong to oilfield chemistry water plugging and profile controlling field.
Background technology
At present, domestic and international oilfield water blockoff, Gu sand, the thick oil thermal extraction sand control, envelope is scurried and the water injection well in oil fields profile control, the permeable grout that uses that waits in shutoff coal seam, the shortcoming that the ubiquity multiviscosisty is fast, the general thickening time was less than 2 hours (G class g cement 40 ℃ of about 90 minutes of thickening times of slurry of water cement ratio 0.44), and use grout oilwell water shutoff, Gu sand, the thick oil thermal extraction sand control, envelope is scurried and the water injection well in oil fields profile control, the shutoff coal seam is permeable waits the site operation operation to need the infusion long period sometimes, be generally 5-10h, or because of mechanical fault have to stop operation the longer time, be generally 10-24h, and this often occurs pit shaft easily and shuts, oil pipe and subsurface tool such as can not pull out at major accident, even the danger that exists whole oil well to scrap, and may cause great financial loss thus.Can use retardant to solve this class problem at present, the retardant of report mainly comprises: weak organic acid class, lignosulfonic acid salt, gluconic acid salt etc., but its slow setting time is still short partially, can't resolve the problems referred to above.The Chinese patent communique discloses a kind of: publication number is the patent of invention " oil well cement retarder " of CN1513797, uses the grout of this retardant, the preparation of G class g cement, 45 ℃ of only 185 minutes thickening times.In addition, the Chinese patent communique also discloses a kind of: application number is 200610014885.6 patent of invention " cement setting retarder and application ", use the grout of retardant, the preparation of G class g cement, 40 ℃ of thickening times also have only 240 minutes, still have short problem of slow setting time.
Summary of the invention
The object of the present invention is to provide long extended slurry of a kind of slow setting time, shut the danger that oil pipe and subsurface tool can not pull out to solve the pit shaft that grout exists when the construction operation such as carry out water blockoff, the anti-sand seal of thick oil thermal extraction is scurried and water injection well profile control, shutoff coal seam be permeable.
For achieving the above object, the technical solution adopted in the present invention is an extended slurry, is made up of following components in weight percentage content: urea 15-35%, suspension agent 0.01-0.1%, cement 30-65%, water 19-35%.
Wherein, described suspension agent is any in organic polymer or the biopolymer, and suspension agent is the commercial goods.
Described cement is any or its combination in Portland cement or the oil well cement.
The compound method of extended slurry of the present invention is: weight percentage is to add the urea of 15-35%, the suspension agent of 0.01-0.1% in the water of 19-35%, and the cement that adds 30-65% after the stirring and dissolving again continues to stir and promptly gets extended slurry of the present invention.Suspension agent among the present invention can be any one commercially available suspension agent.
In the each component of the present invention, what urea played act as: (1) has changed the character of simple water because urea molecule and water molecules form hydrogen bond; (2) existence of urea in the water has reduced the chance that cement granules contacts with water molecules, and both all have the effect of slow setting.The effect that suspension agent is played in extended slurry of the present invention is to delay cement sedimentation accumulative speed in water, so that infusion.Extended slurry of the present invention can make reach 10-48 hour G class g cement 40 ℃ of thickening times of slurry.The key technical indexes of extended slurry of the present invention is: 40 ℃ thickening time 10-48 hour; It solidifies back ultimate compression strength 4-27Mpa; Heatproof after solidifying 〉=300 ℃.
Embodiment
Embodiment 1
Extended slurry of the present invention is prepared from by following components in weight percentage content: urea: 23.4%, and melon glue: 0.05%, the G class g cement: 53%, water: 23.55%.Melon glue in this enforcement is suspension agent.
40 ℃ of thickening time>48 hour (initial consistency 2.6Bc, denseness 0.8Bc after 48 hours); Reinstall mould and wait taking-up in 3 days with fixed attention, ultimate compression strength 12.4MPa.
Embodiment 2
Extended slurry of the present invention is prepared from by following components in weight percentage content: urea: 21.2%, and melon glue: 0.05%, the G class g cement: 57.7%, water: 21.05%.
40 ℃ of thickening time>18 hour (initial consistency 3.3Bc, denseness 6.2Bc after 18 hours); Reinstall mould and wait taking-up in 3 days with fixed attention, ultimate compression strength 15.4MPa.
Embodiment 3
Extended slurry of the present invention is prepared from by following components in weight percentage content: urea: 19.2%, and melon glue: 0.1%, the G class g cement: 61.4%, water 19.3%.
40 ℃ of thickening time>10 hour (initial consistency 3.6Bc, denseness 8.8Bc after 10 hours); Reinstall mould and wait taking-up in 3 days with fixed attention, ultimate compression strength 17.5MPa.
During site operation, in stirred pot, be metered into water, urea, suspension agent by prescription, be stirred to dissolving, be metered into cement again, continue to stir, pump into spearhead, extended slurry, displacing liquid according to this with squeeze note pump or cementing truck, afterwards anti-flushing well, take that steam treatment is short coagulates or heat up automatically to wait and can determine as the case may be with fixed attention in the closing well stratum.
It should be noted last that: above embodiment is only in order to explanation, and unrestricted technical scheme of the present invention, although the present invention is had been described in detail with reference to the foregoing description, those of ordinary skill in the art is to be understood that: still can make amendment or be equal to replacement the present invention, and not breaking away from any modification or partial replacement of the spirit and scope of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.