Anti-leakage cement paste for well cementation

A water leakage prevention and oil well cement technology, which is applied in the field of oil and gas well cementing, can solve the problems of low compressive strength of cement stone, low interface bonding strength, poor dispersion of cement slurry, etc., and achieve high pressure bearing capacity and controllable rheological properties , the effect of effective isolation

Inactive Publication Date: 2019-07-12
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The cement stone formed after the thickening of low-density cement slurry has low compressive strength and low interfacial bonding strength, while the cement slurry added with fiber has poor dispersibility, which is easy to cause problems such as cement agglomeration and pipeline blockage
Therefore, the existing anti-leakage cement slurry is not suitable for porous formations and induced fracture formations caused by pressure differences.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0142] This embodiment provides an anti-leakage cement slurry suitable for well cementing in XX-01 well.

[0143] Well XX-01 is a fractured formation with an average fracture width of 1.0mm. The leakage occurs when the annular pressure is 35.6Mpa, and the maximum annular pressure during cementing is 37.2Mpa. In order to effectively prevent leakage, bridging particles with a particle size of 500 μm to 660 μm are selected to form cement slurry formula 1, which avoids leakage during cementing construction.

[0144] Formula 1: 360g of water, 600g of oil well cement, 10g of bridging particles with a particle size of 500μm to 660μm, 50g of quartz sand, 20g of microsilica fume, 20g of fluid loss reducer, 2g of dispersant, 30g of coagulation accelerator, 3g of suspending agent, Foam agent 20g.

[0145] The anti-leakage cement slurry provided in this example is prepared strictly according to the method specified in Chapter 5 of GB / T 19139.

[0146] According to the method stipulated in...

Embodiment 2

[0149] This embodiment provides an anti-leakage cement slurry suitable for well XX-02 well cementing.

[0150] Well XX-02 is a fractured formation with an average fracture width of 2.0mm. When the annular pressure is 31.5Mpa, the maximum annular pressure is 32.8Mpa. In order to effectively prevent the leakage , select bridging particles with a particle size of 1000 μm to 1300 μm, and add hollow glass microspheres to reduce the density of cement slurry to form cement slurry formula 2, which avoids leakage during cementing construction.

[0151] Formula 2: 530g of water, 750g of oil well cement, 15g of bridging particles with a particle size of 1000μm~1300μm, 75g of quartz sand, 50g of hollow glass microspheres, 35g of silica fume, 25g of fluid loss reducer, 3.7g of dispersant, coagulant accelerator 40g, suspending agent 4g, defoamer 35g.

[0152] The anti-leakage cement slurry provided in this example is prepared strictly according to the method specified in Chapter 5 of GB / T ...

Embodiment 3

[0156] This embodiment provides an anti-leakage cement slurry suitable for well cementing in XX-03 well.

[0157] Well XX-03 is a porous formation with an average pore throat diameter of 3.0mm. When the annular pressure is 26.5Mpa, the maximum annular pressure is 28.8Mpa. In order to effectively prevent the leakage , choose 1500μm~2000μm bridging particles, and add hollow glass microspheres at the same time to reduce the density of cement slurry to form cement slurry formula 3, which avoids leakage during cementing construction.

[0158] Formula 3: 700g of water, 900g of oil well cement, 20g of bridging particles with a particle size of 1500μm-2000μm, 100g of quartz sand, 100g of hollow glass microspheres, 50g of silica fume, 30g of fluid loss reducer, 6g of dispersant, coagulation accelerator 50g, suspending agent 5g, defoamer 50g.

[0159] The anti-leakage cement slurry provided in this example is prepared strictly according to the method specified in Chapter 5 of GB / T 1913...

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Abstract

The invention discloses anti-leakage cement paste for well cementation and belongs to the technical field of well cementation of an oil-gas well. The anti-leakage cement paste is prepared from components as follows: water, oil well cement, bridging particles, quartz sand, silica fume and a cement admixture, wherein the oil well cement has the particle size of 10 mu m to 30 mu m; the particle sizeof the bridging particles is 1 / 2-2 / 3 of the average hole diameter or the average crack width of target stratum; the quartz sand has the particle size of 180 mu m to 425 mu m; the silica fume has the particle size of 0.1 mu m to 0.3 mu m. According to the anti-leakage cement paste, bridge blinding is formed through reasonable gradation of particle materials of different particle sizes, porous stratum with high probability of leakage and inductive crack stratum caused under the action of differential pressure are effectively blocked the pressure bearing capability is high, and well leakage in the well cementation process can be effectively prevented. Cement formed after the anti-leakage cement paste is thickened has high compressive strength and interfacial cementation strength, and effective blocking of an oil and water layer can be realized.

Description

technical field [0001] The invention relates to the technical field of oil and gas well cementing, in particular to an anti-leakage cement slurry for well cementing. Background technique [0002] Well cementing is the process of putting the casing into the well, injecting cement slurry into the annular space between the formation and the casing, and sealing off the oil-water layer in the wellbore after the cement slurry solidifies. one of the important parts. During the cementing process, due to the high-density cement slurry entering the annular space between the casing and the formation, and the high friction in the annular space caused by the high pump pressure during the cementing construction, the pressure difference between the annular slurry column pressure and the formation pressure is greater than that of drilling. During the process, there is a pressure difference between the drilling fluid column pressure of the wellbore and the formation pressure. Therefore, ind...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/00C09K8/467
CPCC04B28/00C04B2201/20C04B2201/50C09K8/467C09K2208/18C04B22/002C04B14/06C04B18/146C04B16/04C04B2103/0068C04B2103/408C04B2103/50C04B14/22
Inventor 唐世忠吴华李娟步宏光吕照鹏曹磊张东艳张新华
Owner PETROCHINA CO LTD
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