CN112552885A

CN112552885A - Superhigh temperature resistant 180 ℃ tackifying type well completion fluid and workover fluid

Info

Publication number: CN112552885A
Application number: CN202011512785.2A
Authority: CN
Inventors: 贾虎; 代昌楼; 牛骋程
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2020-12-20
Filing date: 2020-12-20
Publication date: 2021-03-26
Anticipated expiration: 2040-12-20
Also published as: CN112552885B

Abstract

The invention relates to a 180 ℃ ultrahigh temperature resistant tackifying type well completion fluid and workover fluid, and belongs to the field of oil and natural gas exploitation. The raw materials comprise 1 wt% of stabilizing agent, 1.1 wt% of water-absorbing colloidal particles and the balance of water. After aging for 24 hours at 180 ℃, the viscosity range of the workover fluid is 87-650 mPa · s, and the viscosity can be kept stable at 180 ℃. The high-temperature oil-gas well repairing agent can meet the well repairing requirement of a high-temperature oil-gas well, is simple and convenient to prepare, has strong field operability, and has a good application prospect.

Description

Superhigh temperature resistant 180 ℃ tackifying type well completion fluid and workover fluid

Technical Field

The invention relates to a 180 ℃ ultrahigh temperature resistant tackifying type well completion fluid and workover fluid, and belongs to the field of oil and natural gas exploitation.

Background

The development of deep and ultra-deep layer oil and gas reservoirs is the main force of future oil and gas production. Deep high temperature environments present a severe challenge to downhole working fluids. Carboxymethylcellulose (CMC) and xanthan gum are commonly used in workover operations to increase the viscosity of workover fluids. Carboxymethyl cellulose is water-soluble cellulose ether, and the solution of carboxymethyl cellulose is neutral or slightly alkaline, has the characteristics of thickening, bonding and the like, but can be rapidly degraded at high temperature, and the viscosity is greatly reduced. The tackifying effect of the xanthan gum has good effects on improving the foam stability, the anti-shearing stability and the like, but the xanthan gum has limited high temperature resistance, is easy to generate thermooxidative degradation at high temperature, and has large dosage and high production cost. Therefore, aiming at the problem that the traditional tackifying workover fluid has an unsatisfactory tackifying effect at high temperature, the development of a high-temperature-resistant tackifying completion fluid and workover fluid for circulating well flushing and sand carrying is urgently needed.

The stability of the workover fluid is a key factor of safe and efficient workover operation of the ultrahigh-temperature oil and gas well. The formation temperature is too high in the well repairing process, and the traditional tackifying type well repairing liquid is not resistant to high temperature and easy to leak, and cannot carry sand to be discharged back. Therefore, the related properties of the workover fluid, including basic requirements of no degradation, easy circulation, viscosity increasing and the like at ultrahigh temperature, need to be improved. In 2012, xuyandong et al developed a well repairing fluid (chinese patent: CN 102618225a) which includes a prepared base fluid and an additive, wherein the prepared base fluid is formation water or a mixed solution of the formation water and surface water. Wherein the additives comprise a tackifier, a corrosion inhibitor and a stabilizer. The preparation method has the advantages of good preparation properties of various raw materials and stratum, high temperature resistance of 120 ℃ and high mineralization degree, simple field preparation process and capability of meeting the requirement of protecting a reservoir stratum.

In 2014, Sun Lin et al studied the application of temperature-resistant and salt-resistant xanthan gum system in oil field development. The xanthan gum has a special molecular structure, has obvious technical advantages when being used for oil field development, and has the advantages of strong water solubility, tackifying and thickening properties, salt resistance and pollution resistance, good shear stability, unique rheological property and the like; but are susceptible to thermooxidative degradation at high temperatures. (Sun Lin, Weipeng, Fu Qiang, etc.. the application research progress of the temperature-resistant and salt-resistant type xanthan gum system in the oil field development [ J ]. the application chemical industry, 2014, 43(12):2279-2284.)

In 2017, Chenjiangguang et al developed a tackifying suspension modifier and application thereof (Chinese patent: CN 109384884A), wherein the tackifying suspension modifier comprises the following components: hydroxymethyl starch, N, N' -methylene bisacrylamide and thiosulfate. The viscosity-increasing suspension modifier can be well dissolved in highly mineralized brine workover fluid, and the viscosity of the brine workover fluid is remarkably increased, so that the suspension capacity of the brine workover fluid is improved, and the smooth operation of workover treatment is facilitated.

In 2020, Liu et al studied the properties of nanocomposite films composed of carboxymethylcellulose, cellulose nanofibers and silica, wherein carboxymethylcellulose can be used as a thickener, a flotation agent; but are susceptible to rapid degradation at high temperatures. (Jianxin Liu, et al. nanocomposites membranes from cellulose nanofibers, SiO₂and carboxymethyl cellulose with improved properties. Carbohydrate Polymers[J],2020:11588.)

At present, a solid-free tackifying workover fluid system represented by xanthan gum is completely degraded after being aged for 24 hours at the ultra-high temperature of 180 ℃; CMC is stable for 16h at high temperature of 120 ℃, but is easy to generate thermal oxidative degradation, so that the application of the CMC in the well repair of ultra-high temperature oil and gas wells is limited. Aiming at the problem that the traditional tackifying workover fluid is not ideal in tackifying effect at high temperature, an ultrahigh-temperature tackifying completion fluid and an ultrahigh-temperature tackifying workover fluid need to be designed urgently to ensure safety, smoothness and high efficiency of underground operation.

Disclosure of Invention

The invention aims to develop a viscosity-increasing completion fluid and workover fluid capable of resisting ultra-high temperature of 180 ℃, which are used for circulating sand carrying of oil and gas wells.

The invention provides a technical scheme that:

the viscosity increasing completion and workover fluid resisting superhigh temperature of 180 deg.c consists of stabilizer and water absorbing colloidal particle as main material and is compounded with clear water. The stabilizer is at least one of urotropine, phenolic resin and polyethyleneimine.

In other embodiments of the present invention, the stabilizer is urotropine, phenolic resin, polyethyleneimine diluted with clear water in a certain proportion.

In another embodiment of the present invention, the raw material further includes water-absorbing colloidal particles, the water-absorbing colloidal particles include at least one of SAP-KA01 (trade product, guulite energy technology limited, particle size 0.8-1.5 mm, water absorption rate 67.2) and SHK-220A (trade product, guulite energy technology limited, particle size 0.6-1.0 mm, water absorption rate 152.17), and the water-absorbing colloidal particles include sulfonate groups.

The tackifying type completion fluid and workover fluid resistant to the ultrahigh temperature of 180 ℃ and the preparation method thereof provided by the embodiment of the invention have the beneficial effects that:

the water absorption colloidal particles are partially degraded at high temperature, so that the viscosity of the workover fluid can be improved; the stabilizer can improve the effects of hydraulic control viscosity and stable viscosity of well repair.

Drawings

FIG. 1 is a graph of the viscosity of a completion fluid and a workover fluid according to example 1 of the present invention as a function of temperature;

FIG. 2 is a graph of the viscosity of the completion and workover fluids of example 2 of the present invention as a function of aging time;

FIG. 3 is a graph of viscosity as a function of micelle concentration for completion and workover fluids according to example 3 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following describes a viscous completion fluid and workover fluid resistant to ultra-high temperature of 180 ℃ and a preparation method thereof.

A viscosity-increasing type well completion fluid and workover fluid resisting to ultra-high temperature of 180 ℃ mainly comprises a stabilizer and water-absorbing colloidal particles. The stabilizer is at least one of urotropine, phenolic resin and polyethyleneimine.

In another embodiment of the present invention, the raw material further includes water-absorbing colloidal particles, the water-absorbing colloidal particles are at least one of SAP-KA01 (trade product, guulite energy technology limited, particle size 0.8-1.5 mm, water absorption rate 67.2) and SHK-220A (trade product, guulite energy technology limited, particle size 0.6-1.0 mm, water absorption rate 152.17), and the water-absorbing colloidal particles contain sulfonate groups.

In detail, preparing a viscosity increasing type completion fluid and workover fluid resisting ultra-high temperature of 180 ℃, diluting 1% of a stabilizer by using clear water, adding the diluted stabilizer into quantitative clear water, stirring to uniformly mix the stabilizer, then adding a water absorbing material, and stirring to completely absorb water and swell. The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Adding a certain amount of clear water into a 500ml beaker according to the data in the table 1, then diluting 1% of stabilizer according to the proportion of (urotropine, polyethyleneimine and phenolic resin according to the ratio of 1:1:1) to 20% by using the certain amount of clear water, adding the diluted stabilizer into the beaker, stirring for 15-30 min until the stabilizer is completely and uniformly mixed, then adding 1.1% of SKH-220A water-absorbing colloidal particles, and then fully stirring to ensure that the stabilizer completely absorbs water and swells. Thus preparing the tackifying completion fluid and workover fluid resisting the ultrahigh temperature of 180 ℃. The workover fluid was heated in a water bath to gradually increase from 20 ℃ to 90 ℃ and the viscosity was measured at 10 ℃ intervals using a six-speed rotational viscometer. The results are shown in Table 1.

TABLE 1 viscosity vs. temperature relationship

From the data in table 1, it can be seen that at a given shear rate, the workover fluid viscosity gradually decreases with increasing temperature.

Example 2

Adding a certain amount of clear water into a 500ml beaker according to the data in the table 2, then diluting 1% of stabilizing agent to 20% according to the proportion (polyethyleneimine and phenolic resin are 2:1) by using the certain amount of clear water, adding the diluted stabilizing agent into the beaker, stirring for 15-30 min until the stabilizing agent and the phenolic resin are completely and uniformly mixed, then adding 1.1% of SKH-220A water-absorbing colloidal particles, and then fully stirring to ensure that the water-absorbing colloidal particles completely absorb water and swell. Thus preparing the tackifying completion fluid and workover fluid resisting the ultrahigh temperature of 180 ℃. Then the mixture is put into an aging tank to be aged for 1 to 4 days at 180 ℃, and the viscosity of the mixture is measured by a six-speed rotational viscometer as shown in the following table 2.

TABLE 2 aging time vs. viscosity relationship

From the data in table 2, it can be seen that at a given shear rate, the viscosity of the workover fluid gradually decreases with increasing aging time.

Example 3

Adding quantitative clean water into a 500ml beaker according to the data in the table 3, diluting 1% of stabilizer according to the proportion of (phenolic resin, urotropine and polyethyleneimine are 1:2:1) to 20% by using the quantitative clean water, adding the diluted stabilizer into the beaker, stirring for 15-30 min until the stabilizer is completely and uniformly mixed, then adding 0.7-1.1% of SKH-220A water-absorbing colloidal particles, and then fully stirring to ensure that the stabilizer is completely and fully absorbed with water and swells. Thus preparing the tackifying completion fluid and workover fluid resisting the ultrahigh temperature of 180 ℃. The gel particles were aged at 180 ℃ for 24 hours at a gel particle concentration of 0.7% to 1.1%, and the viscosities measured by a six-speed rotational viscometer are shown in Table 3 below.

TABLE 3 different colloidal particle concentrations vs. viscosity

From the data in table 3, it can be seen that at a given shear rate, the viscosity of the workover fluid gradually increases with increasing density.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. The tackifying completion fluid and workover fluid resistant to the ultrahigh temperature of 180 ℃ is composed of a stabilizer and water-absorbing colloidal particles, and is prepared by using clear water, and is characterized by comprising the following components in percentage by mass: 1 percent of stabilizer and 1.1 percent of water-absorbing colloidal particles.

2. The completion and workover fluids capable of resisting viscosity increase at ultra-high temperature of 180 ℃ according to claim 1, wherein the stabilizer is at least one of urotropin, phenolic resin and polyethyleneimine.

3. The ultra-high temperature 180 ℃ resistant viscosified completion and workover fluids of claim 1, wherein the stabilizing agent is diluted with clear water.

4. The completion and workover fluids capable of resisting viscosity increase at 180 ℃ under ultrahigh temperature as claimed in claim 1, wherein the raw materials further comprise water-absorbing colloidal particles.

5. The completion and workover fluids resistant to viscosity increase at ultra-high temperature of 180 ℃ according to claim 3, wherein the water-absorbing colloidal particles comprise at least one of SAP-KA01 (available from Doulite energy technology Co., Ltd., particle size of 0.8-1.5 mm, water absorption rate of 67.2) and SHK-220A (available from Doulite energy technology Co., Ltd., particle size of 0.6-1.0 mm, water absorption rate of 152.17), and contain sulfonate groups.

6. The preparation method of the superhigh temperature 180 ℃ resistant tackifying type completion fluid and workover fluid according to claim 3 is characterized in that the water-absorbing colloidal particles SHK-220A (the particle size is 0.6-1.0 mm, the water absorption rate is 152.17) are easy to generate knotting when added into the mixed solution, and the colloidal particles cannot automatically absorb water to be completely swollen, so that the colloidal particles are timely stirred to be completely swollen by absorbing water when added.