A kind of low-density cement slurry system for deep water surface layer cementing and its application

Abstract

The invention discloses a low-density cement slurry system for deepwater surface layer well cementation and application thereof. The low-density cement slurry system comprises the following components in parts by weight: 100 parts of cement, 5-40 parts of liquid suspending agent, 5-40 parts of liquid reinforcer, 4-10 parts of liquid water-loss control agent, 2-10 parts of early strength agent, 0.05-1.5 parts of defoaming agent and 50-250 parts of fresh water or sea water. The additives of the cement slurry system have definite performance and are all liquids; and the system is simple in composition, high in slurry making rate and excellent in low-temperature early-strength performance.

Description

technical field

[0001] The present application relates to but not limited to a cement slurry system, in particular to but not limited to a low-density cement slurry system for deep-water surface well cementing and its application. Background technique

[0002] Deepwater cementing is the prerequisite and important guarantee for the effective exploration and development of deepwater oil and gas resources. Among them, deepwater surface cementing is the initial cementing operation of deepwater oil and gas well cementing procedures. Narrow, the formation is easy to leak, so low-density cement slurry is usually used (usually density range: 1.30-1.60g / cm 3 ) for deepwater surface cementing operations.

[0003] There are usually two ways to construct low-density cement slurry. The first is to add substances such as water glass and clay as suspending agents (Extender) to the cement slurry to provide stability for low-density cement slurry. The thickening time of low-density cement ...

Examples

Embodiment 1

[0036] Preparation of liquid suspension:

[0037] Weigh and mix 50g of silicon dioxide liquid LUDOX HS 40, 15g of polyurethane suspending agent ACRYSOL RM-8W, and 35g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX HS40 is 12nm, the content is 40%, and pH=9.5.

[0038] Preparation of liquid early strength agent:

[0039] Nano Ca(OH) 2 Preparation of:

[0040] (1) Weigh 11.1g of calcium chloride and 40g of deionized water, place them in a beaker and stir to dissolve them, and place them in a water bath at 60°C after they are completely dissolved;

[0041] (2) add 4g polycarboxylate dispersant in beaker, stir;

[0042] (3) Weigh 10 g of sodium hydroxide and dissolve it in 20 g of deionized water, put it into the dropping funnel after it is completely dissolved, add the sodium hydroxide solution into the beaker in a dropwise manner, and stir while adding it dropwise.

[0043] (4) Suction filtr...

Embodiment 2

[0057] Preparation of liquid suspension:

[0058] Weigh and mix 50g of silicon dioxide liquid LUDOX AS 40, 20g of polyurethane suspending agent ACRYSOL RM-8W, and 30g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX AS 40 is 22nm, the content is 40%, and the pH=9.4.

[0059] Preparation of liquid early strength agent:

[0060] (1) Weigh 1.38g xanthan gum, slowly add it into a beaker filled with 100g deionized water, and stir for 1h to form a uniform viscous solution;

[0061] (2) Weigh 142g K 2 SO 4 and 148g Na 2 SO 4 and 16g Na 2 SiO 3 , added to 80g of ethylene glycol, stirred to disperse evenly;

[0062] (3) Weigh 80g of the solution obtained in step (1) and add it to the liquid obtained in step (2), and stir to make it evenly mixed;

[0063] (4) Add the nano-Ca(OH) prepared by 28g embodiment 1 2 , stir to make it evenly mixed;

[0064] (5) Add 7.2g triethanolamine, stir to make it ...

Embodiment 3

[0071] Preparation of liquid suspension:

[0072] Weigh and mix 55g of silicon dioxide liquid LUDOX SM 30, 25g of polyurethane suspending agent ACRYSOL RM-2020W, and 20g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX SM30 is 7nm, the content is 30%, pH=10.

[0073] Preparation of liquid early strength agent:

[0074] (1) Weigh 1.2g xanthan gum, slowly add it into a beaker filled with 100g deionized water, and stir for 1h to form a uniform viscous solution;

[0075] (2) Weigh 160g Na 2 SO 4 and 3g Na 2 SiO 3 , added to 50g of ethylene glycol, stirred to disperse evenly;

[0076] (3) Weigh 50g of the solution obtained in step (1) and add it to the liquid obtained in step (2), and stir to make it evenly mixed;

[0077] (4) add the nano-Ca(OH) that 20g embodiment 1 prepares 2 , stir to make it evenly mixed;

[0078] (5) Add 3.8g triethanolamine, stir to make it mix evenly;

[0079] (6) Ad...

technical field

[0001] The present application relates to but not limited to a cement slurry system, in particular to but not limited to a low-density cement slurry system for deep-water surface well cementing and its application. Background technique

[0002] Deepwater cementing is the prerequisite and important guarantee for the effective exploration and development of deepwater oil and gas resources. Among them, deepwater surface cementing is the initial cementing operation of deepwater oil and gas well cementing procedures. Narrow, the formation is easy to leak, so low-density cement slurry is usually used (usually density range: 1.30-1.60g / cm 3 ) for deepwater surface cementing operations.

[0003] There are usually two ways to construct low-density cement slurry. The first is to add substances such as water glass and clay as suspending agents (Extender) to the cement slurry to provide stability for low-density cement slurry. The thickening time of low-density cement ...

Examples

Embodiment 1

[0036] Preparation of liquid suspension:

[0037] Weigh and mix 50g of silicon dioxide liquid LUDOX HS 40, 15g of polyurethane suspending agent ACRYSOL RM-8W, and 35g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX HS40 is 12nm, the content is 40%, and pH=9.5.

[0038] Preparation of liquid early strength agent:

[0039] Nano Ca(OH) 2 Preparation of:

[0040] (1) Weigh 11.1g of calcium chloride and 40g of deionized water, place them in a beaker and stir to dissolve them, and place them in a water bath at 60°C after they are completely dissolved;

[0041] (2) add 4g polycarboxylate dispersant in beaker, stir;

[0042] (3) Weigh 10 g of sodium hydroxide and dissolve it in 20 g of deionized water, put it into the dropping funnel after it is completely dissolved, add the sodium hydroxide solution into the beaker in a dropwise manner, and stir while adding it dropwise.

[0043] (4) Suction filtr...

Embodiment 2

[0057] Preparation of liquid suspension:

[0058] Weigh and mix 50g of silicon dioxide liquid LUDOX AS 40, 20g of polyurethane suspending agent ACRYSOL RM-8W, and 30g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX AS 40 is 22nm, the content is 40%, and the pH=9.4.

[0059] Preparation of liquid early strength agent:

[0060] (1) Weigh 1.38g xanthan gum, slowly add it into a beaker filled with 100g deionized water, and stir for 1h to form a uniform viscous solution;

[0061] (2) Weigh 142g K 2 SO 4 and 148g Na 2 SO 4 and 16g Na 2 SiO 3 , added to 80g of ethylene glycol, stirred to disperse evenly;

[0062] (3) Weigh 80g of the solution obtained in step (1) and add it to the liquid obtained in step (2), and stir to make it evenly mixed;

[0063] (4) Add the nano-Ca(OH) prepared by 28g embodiment 1 2 , stir to make it evenly mixed;

[0064] (5) Add 7.2g triethanolamine, stir to make it ...

Embodiment 3

[0071] Preparation of liquid suspension:

[0072] Weigh and mix 55g of silicon dioxide liquid LUDOX SM 30, 25g of polyurethane suspending agent ACRYSOL RM-2020W, and 20g of deionized water, and stir evenly to obtain a liquid suspending agent. Among them, the particle size of silicon dioxide in LUDOX SM30 is 7nm, the content is 30%, pH=10.

[0073] Preparation of liquid early strength agent:

[0074] (1) Weigh 1.2g xanthan gum, slowly add it into a beaker filled with 100g deionized water, and stir for 1h to form a uniform viscous solution;

[0075] (2) Weigh 160g Na 2 SO 4 and 3g Na 2 SiO 3 , added to 50g of ethylene glycol, stirred to disperse evenly;

[0076] (3) Weigh 50g of the solution obtained in step (1) and add it to the liquid obtained in step (2), and stir to make it evenly mixed;

[0077] (4) add the nano-Ca(OH) that 20g embodiment 1 prepares 2 , stir to make it evenly mixed;

[0078] (5) Add 3.8g triethanolamine, stir to make it mix evenly;

[0079] (6) Ad...

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