Low-density water base drilling fluid capable of resisting ultra-high temperature of 248 DEG C as well as preparation method and application thereof

A water-based drilling fluid, low-density technology, used in chemical instruments and methods, earth-moving drilling, flushing wells, etc.

CN108659801AActive Publication Date: 2018-10-16CHENGDU UNIVERSITY OF TECHNOLOGY
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2018-10-16

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Abstract

The invention relates to a low-density water base drilling fluid capable of resisting ultra-high temperature of 248 DEG C as well as a preparation method and application thereof. The drilling fluid isprepared from the following raw materials: 100 parts of pulp blending water, 0.2-0.3 part of sodium carbonate, 1.5-4 parts of sodium bentonite, 0-0.5 part of caustic soda flake, 0.3-0.5 part of deoxidant, 0.3-0.7 part of zwitter-ion hydrophobic associated polymer filtrate reducer, 0.5-1.2 parts of anionic type polymer filtrate reducer, 3-5 parts of sulfomethylation formoldehyde resin type II, 3-5parts of sulfomethylation lignite resin, 2-4 parts of high softening point sulfonated bitumen, 1-3 parts of modified graphitic lubricant, 1-3 parts of polymeric alcohol, 0-6 parts of No.5 white oil,0-1 part of emulsifier, 0-2 parts of polycarboxylate flow type conditioning agent, 3-5 parts of ultra-high temperature blocking agent and 0-20 parts of API (American Petroleum Institute) standard barite. The drilling fluid is suitable for a stratum of which the temperature is 248 DEG C. The ultra-high temperature low-density water base drilling fluid disclosed by the invention has the advantages of high thermal stability under an ultra-high temperature condition, simpleness in performance maintenance and low cost, and the rheological property of the drilling fluid is easy in regulation and control.
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Description

Technical field:

[0001] The invention relates to an ultra-high temperature-resistant low-density polysulfide water-based drilling fluid for ultra-deep well drilling and its preparation method and application, belonging to the technical field of drilling fluid in oil and natural gas drilling engineering, deep exploration drilling engineering and geothermal well drilling engineering . Background technique:

[0002] With the development of my country's oil and gas industry, oil and gas exploration areas are gradually expanding from land to deep sea, and target layers are expanding from shallow to deep and ultra-deep layers. Ultra-deep layers will be one of the most important development areas for my country's oil industry in the future. During the drilling process of ultra-deep wells, the bottom of the well is under ultra-high temperature and high pressure conditions. The drilling section is long and there are large sections of open holes, and many complex formations must be dr...

Examples

Embodiment 1

[0092] 1.1 Drilling fluid formula composition: 400mL mixing water + 8g sodium bentonite + 0.4g sodium carbonate + 0.6g flaky sodium hydroxide + 2g anhydrous sodium sulfite + 2g ultra-high temperature resistant compound salt high relative molecular weight amphoteric ion hydrophobic association polymerization Fluid loss reducer + 2.8g ultra-high temperature salt-resistant anionic polymer fluid loss reducer + 12g sulfomethylated phenolic resin + 15g sulfomethyl lignite resin + 12g high softening point sulfonated asphalt + 6g modified Graphite lubricant + 8g polymer alcohol + 6g No. 5 white oil + 1.2g Span 80 + 6g anti-ultra-high temperature polycarboxylate flow regulator + 20g ultra-fine calcium carbonate + barite weighted to 1.10g / cm 3 .

[0093] 1.2 Preparation method: Add 400mL of mixing water into a high stirring cup, under the condition of high-speed stirring (8000~12000rpm), add 8g of sodium bentonite, 0.4g of sodium carbonate and 0.6g of flake sodium hydroxide in sequence,...

Embodiment 2

[0108] As described in Example 1, the difference is the composition of the drilling fluid and the density of the drilling fluid.

[0109] 2.1 Drilling fluid formula composition: 400mL mixing water + 16g sodium bentonite + 0.8g sodium carbonate + 1.2g flaky sodium hydroxide + 2.0g anhydrous sodium sulfite + 2.0g ultra-high temperature resistant compound salt high relative molecular weight amphoteric ion hydrophobic Polymer fluid loss reducer+2.0g ultra-high temperature salt-resistant anionic polymer fluid loss reducer+12g sulfomethylated phenolic resin+17g sulfomethyl lignite resin+12g high softening point sulfonated asphalt+ 6g modified graphite lubricant + 6g polymer alcohol + 6g No. 5 white oil + 1.2g Span 80 + 2.0g anti-ultra-high temperature polycarboxylate flow regulator + 20g ultra-fine calcium carbonate + barite weighted to 1.04g / cm 3 .

[0110] 2.2 Preparation method: Add 400mL of mixing water into a high stirring cup, under the condition of high-speed stirring (800...

Embodiment 3

[0115] As described in Example 1 and Example 2, the difference is the composition of the drilling fluid and the density of the drilling fluid.

[0116] 3.1 Drilling fluid formula composition: 400mL mixing water + 8g sodium bentonite + 0.4g sodium carbonate + 1.2g flaky sodium hydroxide + 2g anhydrous sodium sulfite + 2.8g ultra-high temperature resistant compound salt high relative molecular weight amphoteric ion hydrophobic association Polymer fluid loss reducer + 2.4g ultra-high temperature anti-salt medium relative molecular weight anionic polymer fluid loss reducer + 16g sulfomethylated phenolic resin + 16g sulfomethyl lignite resin + 12g high softening point sulfonated asphalt + 4g Modified graphite lubricant + 8g polyalcohol + 4g No. 5 white oil + 1.2g Span 80 + 4g anti-ultra-high temperature polycarboxylate flow regulator + 20g ultra-fine calcium carbonate + barite weighted to 1.30g / cm 3 .

[0117] 3.2 Preparation method: Add 400mL of mixing water into a high stirring ...