Plugging agent for drilling fluid and preparation method thereof

The technology of a plugging agent and drilling fluid, which is applied in the field of oil drilling plugging, can solve the problems of high product hardness, low plugging strength, weak scour ability, etc. High temperature resistance effect

Active Publication Date: 2021-05-04
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although compared with the previous patent, the plugging ability has been improved, but there are also problems such as the formation fluid is easily diluted by the formation fluid, and the cementation strength of the diluted plugging material will be greatly reduced, resulting in a decrease in the retention capacity.
[0006] CN102618230A discloses a controllable cross-linked gel water plugging and leakage plugging material for oil and gas fields. The plugging material is first made of water-absorbing resin by reacting organic monomers in an aqueous solution with an initiator, and then continues to react repeatedly in the oil phase. The particles obtained by wrapping are added into the HPAM aqueous solution for cross-linking reaction to obtain an immobile gel, which can plug fracture-type and karst-cavity formations. poor sex
[0007] CN110003864A discloses a plugging agent in drilling fluid and its preparation method. The method uses resin as the main agent and adopts a latent curing agent with microcapsule structure. The core layer is an amine curing agent, and the wall layer is a high-toughness engineering Plastic polymers, this method can solve the contradiction between the long construction period and fast curing of the plugging resin, but due to the use of high-tough engineering plastic polymers in this method, if the thickness of the capsule wall is not well controlled, the capsule wall will be difficult to break during use Or it cannot be completely broken, so that the curing agent cannot fully react with the resin, affecting the curing effect
In addition, since the main agent is resin, the cured product has high hardness, poor viscoelasticity, poor adaptability to different cracks and hole sizes, and it is difficult to achieve a good plugging effect
[0008] At present, although a large number of researches on plugging materials have been carried out for the leakage of large fractures and caves, there are still problems such as poor retention ability of plugging materials in the leakage channel, weak resistance to water dilution, weak scouring ability, and low plugging strength.
Especially under the condition of high temperature use, the success rate of leak plugging of large cracks and karst caves is very low, and the loss is serious

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Add 48g of m-xylylenediamine and 31.5g of phenol into the reactor, stir and heat up to dissolve, slowly add 35.7g of 37wt% formaldehyde aqueous solution dropwise at 80°C, drop it over 60min, then react at 90°C for 3.0h, and raise the temperature To 175°C, vacuum dehydration to obtain the accelerator.

[0045] Dissolve 25g of polymethyl methacrylate in dichloromethane, add 73.6g of WE-8325 water-based epoxy curing agent and 16.4g of the accelerator prepared above, and divide evenly for 20min with a homogenizer to form a dispersed phase. Add 1.0% sodium lauryl sulfate aqueous solution into the three-necked flask as the continuous phase. At room temperature, add the dispersed phase drop by drop to the continuous phase while stirring, and emulsify with high-speed stirring at a stirring speed of 2500r / min; then place the three-necked flask in a constant temperature water bath at 40°C, reduce the stirring speed to 550r / min, The reaction time is 3.5 h until the dichloromethan...

Embodiment 2

[0048] Add 64.2g of ethylenediamine and 37.5g of phenol into the reactor, stir and heat up to dissolve, slowly add 49.2g of 37wt% formaldehyde aqueous solution dropwise at 55°C, drop it in 70min, then react at 85°C for 2.5h, and heat up to 170°C, vacuum dehydration to obtain accelerator.

[0049] Dissolve 28g of polymethyl methacrylate in dichloromethane, add 100g of WE-8300 water-based epoxy curing agent and 31.3g of the accelerator prepared above, and divide evenly for 25min with a homogenizer to form a dispersed phase. Add 1.0% sodium lauryl sulfate aqueous solution into the three-necked flask as the continuous phase. At room temperature, add the dispersed phase drop by drop to the continuous phase while stirring, and emulsify with high-speed stirring at a stirring speed of 2200r / min; then place the three-necked flask in a constant temperature water bath at 45°C, reduce the stirring speed to 650r / min, The reaction time is 5 hours until the dichloromethane is completely vol...

Embodiment 3

[0052] Add 47.6g m-xylylenediamine and 24.2g phenol into the reactor, stir and raise the temperature to dissolve, slowly add 35.7g aqueous solution containing 35wt% formaldehyde dropwise at 75°C, drop it in 45min, then react at 100°C for 3.5h, Raise the temperature to 180°C, vacuumize and dehydrate to obtain the accelerator.

[0053] Dissolve 35g of polymethyl methacrylate in dichloromethane, add 87.2g of WE-8309 water-based epoxy curing agent and 24.8g of the accelerator prepared above, and divide evenly for 30min with a homogenizer to form a dispersed phase. Add 1.0% sodium lauryl sulfate aqueous solution into the three-necked flask as the continuous phase. At room temperature, add the dispersed phase drop by drop to the continuous phase while stirring, and emulsify with high-speed stirring at a stirring speed of 2600r / min; then place the three-necked flask in a constant temperature water bath at 40°C, reduce the stirring speed to 700r / min, The reaction time is 4.5 h until ...

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Abstract

The invention discloses a plugging agent for drilling fluid and a preparation method thereof. The plugging agent is prepared from the following components in parts by weight: 100 parts of emulsified asphalt, 10-40 parts of water-borne epoxy resin, 10-40 parts of a microcapsule modifier and 1-10 parts of cement. The plugging agent can effectively reside at entrances of malignant leakage strata such as large cracks and karst caves to form solid sealing, and particularly, the retention plugging capacity and the water washing resistance are improved at high temperature and high pressure, so that the plugging success rate is increased.

Description

technical field [0001] The invention relates to the field of oil drilling plugging, in particular to a plugging agent for drilling fluid and a preparation method thereof. Background technique [0002] In the oil and gas drilling process, lost circulation is a ubiquitous and often encountered complex problem. Downhole accidents caused by lost circulation are extremely harmful to drilling and completion, and have always been an urgent problem to be solved in the field of petroleum engineering. During drilling operations, once lost circulation occurs, it will not only delay time, lose drilling fluid, and damage oil and gas layers, but also may cause well wall instability, leading to a series of complex situations and accidents such as well collapse, pipe sticking, and blowout, and even lead to wellbore failure. scrapped, resulting in significant economic losses. [0003] Especially in the process of drilling deep oil and gas wells in alpine areas, the number of large fracture...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/03C09K8/42
CPCC09K8/426C09K8/03
Inventor 傅丽郭皎河郭小圣刘成吴晓颖
Owner CHINA PETROLEUM & CHEM CORP
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