Low-molecular-weight polymer fracturing liquid

A polymer and low-molecular technology, applied in the field of oil field fracturing, can solve the problems of adjustment and control of fracturing fluid cross-linking time, narrow application range, etc., and achieve the effect of small reservoir damage and low friction

Active Publication Date: 2013-12-04
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages and deficiencies of this formula are: ① It does not explain how to adjust and control the crosslinking time of the fracturing fluid; ② How to stabilize the clay minerals in the formation rock; ③ No low-temperature activator and temperature stabilizer are added, so the scope of application is narrow

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] Example 1: Well Ba 10-23 has a fracturing section of 1307.4 to 1339.2 m and a reservoir temperature of 53°C.

[0056]Low-molecular polymer fracturing fluid: the weight percentage of each component is: XT-3 low-molecular polymer thickener, 0.3%; potassium chloride, 2%; acetic acid, 0.02%; non-ionic drainage aid, 0.5% ; Sodium bisulfite, 0.15%; Cross-linking agent, 0.15%; Ammonium persulfate, 0.05-0.15%; The rest is water. The sum of the weight percentages of each component is 100%.

[0057] Preparation method of low molecular polymer fracturing fluid:

[0058] Step 1: preparing a cross-linking agent: the cross-linking agent is composed of agent A and agent B, the weight ratio of agent A to agent B is 4:1, and they are mixed uniformly to obtain a cross-linking agent.

[0059] The weight percentage of each component of agent A is: aluminum chloride, 10%; zirconium oxychloride, 10%; sodium hydroxide, 8%; glycerin, 10%; lactic acid, 10%; methanol, 20%; water, 32% .

[00...

Embodiment 2

[0074] Example 2: Well Tai 27-13 has a fracturing section of 1764.0-1755.4m, and the reservoir temperature is 73°C.

[0075] Molecular polymer fracturing fluid: the weight percentage of each component is: 0.35% XT-3 low-molecular polymer thickener; 1% potassium chloride; 0.022% acetic acid; 0.5% non-ionic drainage aid; 0.2% crosslinking agent; 0.02-0.15% ammonium persulfate; the rest is water, and the sum of the weight percentages of each component is 100%.

[0076] Preparation method of low molecular polymer fracturing fluid:

[0077] Step 1 and Step 2: The preparation of the crosslinking agent and the preparation of the non-ionic drainage aid are the same as in Example 1.

[0078] Step 3: Preparation of fracturing fluid raw glue: add water to the liquid mixing tank, add acetic acid under stirring condition, stir well, then add XT-3 low molecular weight polymer thickener, potassium chloride and drainage aid , Stir for more than 10 minutes after adding the materials, so that...

Embodiment 3

[0081] Example 3: Well Aer 3-50 has a fractured section of 2144.0-2614.0 m, and the reservoir temperature is 83°C.

[0082] Low-molecular polymer fracturing fluid: the weight percentage of each component is: 0.4% XT-3 low-molecular polymer thickener; 1% potassium chloride; 0.025% acetic acid; 0.5% non-ionic drainage aid; Joint agent, 0.015-0.15% ammonium persulfate; the rest is water, and the sum of the weight percentages of each component is 100%.

[0083] Preparation method of low molecular polymer fracturing fluid:

[0084] Step 1 and Step 2: The preparation of the crosslinking agent and the preparation of the non-ionic drainage aid are the same as in Example 1.

[0085] Step 3: The preparation of the original fracturing fluid glue solution is the same as that in Example 2.

[0086] Step 4: When the fracturing fluid is injected into the fracturing fluid, a crosslinking agent and ammonium persulfate are added to the fracturing fluid.

[0087] Effect of use: 2.69m oil prod...

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Abstract

Low-molecular-weight polymer fracturing liquid is mainly applied to fracturing modification of low-infiltration alkali-sensitive reservoirs and water injection wells and consists of, in weight percentage, 0.25-0.6% of XT-3 low-molecular-weight polymer densifier, 0.2-0.6% of crosslinking agent, 0.5-2% of potassium chloride, 0.02-0.08% of crosslinking modifier, 0.2-0.5% of cleanup additive, 0.0001-0.15% of ammonium persulfate and the balance of water. The low-molecular-weight polymer fracturing liquid is prepared by adding clean water into a liquid preparation tank firstly, adding acetic acid during stirring, then adding the XT-3 low-molecular-weight polymer densifier, the potassium chloride and the cleanup additive after uniformly stirring, stirring more than 10 minutes after materials are added until density or viscosity of upper liquid and lower liquid in the liquid preparation tank are uniform, and finally, adding the crosslinking agent and adhesive breaker according to requirements during fracturing. The low-molecular-weight polymer fracturing liquid has the advantages that residues of the fracturing liquid and alkali-sensitive damages of the reservoirs are solved, the fracturing liquid is prepared and used conveniently, temperature resistance and shearing resistance are fine, and the requirements of fracturing modification of low infiltration and alkali-sensitive reservoirs can be met.

Description

technical field [0001] The invention relates to the technical field of oil field fracturing. The patent of the invention belongs to the fracturing fluid used for oil and gas field fracturing reconstruction, which is a low-molecular polymer fracturing fluid for low-permeability and alkali-sensitive reservoirs. Background technique [0002] In the process of exploration and development of oil and gas reservoirs, some low-permeability and alkali-sensitive reservoirs are often found. For example, the Uliastai Block of Erlian Oilfield in North China belongs to low porosity, low permeability and ultra-low permeability (porosity 8 ~10%; stratum test interpretation permeability 0.05~1.02×10 -3 μm 2 ) Lithology-structural reservoirs, the reservoirs are mainly conglomerate and glutenite, with moderate water sensitivity and alkali sensitivity. Due to the alkaline cross-linking environment and some residues in the commonly used hydroxypropyl guar gum fracturing fluid, the damage to th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K8/68
Inventor 崔会杰余东合车航李建召修书志
Owner PETROCHINA CO LTD
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