CN112608724B - Gel spacer fluid for oil and gas fields and preparation method thereof - Google Patents

Abstract

The invention discloses a gel spacer fluid for oil and gas fields, which mainly comprises the following raw materials by weight and 100 percent, wherein the modified vegetable gum accounts for 20 to 25 percent, the flow pattern regulator accounts for 3 to 6 percent, the N-diethylaniline accounts for 0.1 to 0.4 percent, and the balance is water; wherein, the modified vegetable gum is prepared by uniformly mixing 0.1 to 0.6 part of xanthan gum, 0.04 to 0.3 part of guar gum, 0.2 to 0.6 part of sesbania gum, 0.1 to 1.2 parts of fenugreek gum, 0.01 to 0.15 part of konjac gum and 0.01 to 0.2 part of locust bean gum; wherein, the flow pattern regulator is prepared from polymeric alcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1-2. In addition, the invention also relates to a preparation method of the gel spacer fluid for the oil and gas field. The gel isolation liquid has a good isolation effect and good pollution resistance.

Description

Gel spacer fluid for oil and gas fields and preparation method thereof

Technical Field

The invention relates to the technical field of additives of well completion fluids and workover fluids of oil and gas fields, in particular to a gel spacer fluid for the oil and gas fields; in addition, the invention also relates to a preparation method of the gel spacer fluid for the oil and gas field.

Background

In recent years, the problem of poor compatibility of working fluid and drilling fluid and the like during well completion and workover is increasingly prominent, and the problems of thickening, sedimentation and caking appear after the completion fluid or workover fluid is mixed with the drilling fluid. Through the analysis and research on the contact pollution factors of the completion fluid or workover fluid and the drilling fluid, the gel spacer fluid for the oil-gas field is developed. The application of the gel spacer fluid can effectively prevent the completion fluid or workover fluid from being mixed with the drilling fluid and prevent the phenomena of thickening, sedimentation and agglomeration. The existing isolation liquid system has poor isolation effect and pollution resistance.

Disclosure of Invention

The invention aims to provide a gel isolation liquid for an oil-gas field, which has a good isolation effect and good anti-pollution capability; in addition, the invention also discloses a preparation method of the gel spacer fluid for the oil and gas field.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a gel spacer fluid for oil and gas fields comprises the following raw materials by weight and 100%, wherein the modified vegetable gum accounts for 20-25%, the flow pattern regulator accounts for 3-6%, the N-diethylaniline accounts for 0.1-0.4%, and the balance is water;

wherein, the modified vegetable gum is prepared by uniformly mixing 0.1 to 0.6 part of xanthan gum, 0.04 to 0.3 part of guar gum, 0.2 to 0.6 part of sesbania gum, 0.1 to 1.2 parts of fenugreek gum, 0.01 to 0.15 part of konjac gum and 0.01 to 0.2 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polymeric alcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1-2.

A preparation method of gel spacer fluid for oil and gas fields comprises the following steps,

step 1: weighing the component materials according to the formula ratio, and respectively and fully mixing the component materials uniformly according to the proportion;

and 2, step: taking the water in the formula, placing the water in a preparation container, and heating the water to 35-40 ℃;

and step 3: adding a flow pattern regulator and N-diethylaniline, and stirring for 10-15min to fully mix the flow pattern regulator, the N-diethylaniline and water;

and 4, step 4: slowly adding the modified vegetable gum into a preparation container, slowly stirring for 1-3min at a speed of 20-40r/min, and after stirring is finished, increasing the rotation speed to 60-80r/min, and stirring for 20-30min to obtain the gel isolation liquid.

And (3) further optimizing, in the step 2, taking the formula water, placing the formula water in a preparation container, and heating the water to 38 ℃.

And 4, slowly adding the modified vegetable gum into the preparation container, slowly stirring for 2min at the speed of 30r/min, and after stirring is finished, increasing the rotating speed to 70r/min and stirring for 25min.

Compared with the prior art, the invention has the following beneficial effects:

the invention mainly comprises 20-25% of modified vegetable gum, 3-6% of flow pattern regulator, 0.1-0.4% of N-diethylaniline and the balance of water; the modified vegetable gum is mainly prepared by uniformly mixing 0.1 to 0.6 part of xanthan gum, 0.04 to 0.3 part of guar gum, 0.2 to 0.6 part of sesbania gum, 0.1 to 1.2 parts of fenugreek gum, 0.01 to 0.15 part of konjac gum and 0.01 to 0.2 part of locust bean gum; wherein, the flow pattern regulator is prepared by polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1-2; the invention has better isolation effect and better anti-pollution capability; the hydrophobic and oleophobic effects are better; without affecting the drilling fluid settling or settling significantly or causing the drilling fluid to thicken significantly to lose its mobility.

Detailed Description

The present invention will be further described with reference to the following examples, which are intended to illustrate only some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, other embodiments used by those skilled in the art without any creative effort belong to the protection scope of the present invention.

Example one

The embodiment discloses a gel spacer fluid for oil and gas fields, which mainly comprises the following raw materials, by weight and 100%, 20% of modified vegetable gum, 3% of flow pattern regulator, 0.1% of N-diethylaniline and the balance of water;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.1 part of xanthan gum, 0.04 part of guar gum, 0.2 part of sesbania gum, 0.1 part of fenugreek gum, 0.01 part of konjac gum and 0.01 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1.

The specific preparation method comprises the following steps: step 1: weighing the component materials according to the formula ratio, and respectively and fully mixing the component materials uniformly according to the proportion;

and 2, step: taking the water in the formula, placing the water in a preparation container, and heating the water to 38 ℃;

and step 3: adding flow pattern regulator and N-diethylaniline, stirring for 12min to fully mix the flow pattern regulator and the N-diethylaniline with water;

and 4, step 4: slowly adding the modified vegetable gum into a preparation container, slowly stirring for 1-3min at 30ad/min, and after stirring, increasing the rotation speed to 70r/min and stirring for 25min to obtain the gel isolation solution.

In the invention, the modified vegetable gum is mainly prepared by uniformly mixing xanthan gum, guar gum, sesbania gum, fenugreek gum, konjac gum and locust bean gum; the natural polysaccharide high molecular compounds are adopted, so that the water-soluble and cross-linking properties are good, and the viscosity is high; under the action of polymeric alcohol, carboxymethyl cellulose, hydroxymethyl cellulose and N-diethylaniline, the modified vegetable gum can better form a gum system with the aqueous solution; so that the viscosity is better and the high temperature resistance is improved. The invention has better isolation effect and better hydrophobic and oleophobic effects; the drilling fluid has good anti-pollution capacity, and can not influence the serious sedimentation or precipitation of the drilling fluid or cause the drilling fluid to be thickened seriously to lose fluidity.

Example two

The embodiment discloses a gel spacer fluid for oil and gas fields, which mainly comprises the following raw materials by weight and 100%, wherein 23% of modified vegetable gum, 5% of flow pattern regulator, 0.3% of N-diethylaniline and the balance of water are added;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.4 part of xanthan gum, 0.2 part of guar gum, 0.4 part of sesbania gum, 0.8 part of fenugreek gum, 0.1 part of konjac glucomannan and 0.15 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 2.8.

The specific preparation method comprises the following steps:

step 1: weighing the component materials according to the formula ratio, and respectively and fully mixing the component materials uniformly according to the proportion;

and 2, step: taking the water in the formula, placing the water in a preparation container, and heating the water to 35 ℃; therefore, the mixing of the raw materials of each component can be accelerated, and the mixing efficiency is improved.

And step 3: adding flow pattern regulator and N-diethylaniline, stirring for 10min to fully mix the flow pattern regulator and the N-diethylaniline with water;

and 4, step 4: slowly adding the modified vegetable gum into a preparation container, slowly stirring for 1min at 20r/min, and after stirring, increasing the rotation speed to 60r/min, and stirring for 20min to obtain a gel isolation solution; because the formed gel spacer fluid has better viscosity, the requirement on a stirring device can be effectively reduced by adopting a low-speed stirring mode.

EXAMPLE III

The embodiment discloses a gel spacer fluid for oil and gas fields, which mainly comprises the following raw materials in percentage by weight and 100 percent, wherein the raw materials comprise 25 percent of modified vegetable gum, 6 percent of flow pattern regulator, 0.4 percent of N-diethylaniline and the balance of water;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.6 part of xanthan gum, 0.3 part of guar gum, 0.6 part of sesbania gum, 1.2 parts of fenugreek gum, 0.15 part of konjac glucomannan and 0.2 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 2.

The specific preparation method comprises the following steps:

step 1: weighing the component materials according to the formula ratio, and respectively and fully mixing the components uniformly according to the proportion;

and 2, step: taking the water in the formula, placing the water in a preparation container, and heating the water to 40 ℃;

and 3, step 3: adding flow pattern regulator and N-diethylaniline, stirring for 15min to fully mix the flow pattern regulator and the N-diethylaniline with water;

and 4, step 4: slowly adding the modified vegetable gum into a preparation container, slowly stirring for 3min at 40r/min, and after stirring, increasing the rotation speed to 80r/min, and stirring for 30min to obtain the gel isolation solution.

To better demonstrate the performance of the present invention, the gel spacer prepared in example one was used in the following experiment:

1. fluidity test

Approximately 145mL of liquid was measured, the liquid was poured onto a smooth glass panel, and the diameter of the circular liquid surface was measured quickly, which is the measurement data of fluidity.

The test results are as follows:

test items	Numerical value
		Fluidity in cm	13.5
Reading at 600 revolutions	30-80 wave motion
		Freezing point, deg.C	-18
ρ,g/cm3	0.96
		pH	8.5-9

2. Hydrophobic oleophobic Property test

50mL tap water and 50mL gel isolation liquid were added to a 100mL stoppered measuring cylinder, the stoppered stopper was capped, turned upside down 10 times by hand, left standing for 24h, and the volume of the gel interface was observed. The oil repellency was measured by changing only tap water to 0# diesel oil in the same manner as in the above method.

The test results are as follows:

test item	Data and phenomena
		Hydrophobicity	The upper layer is 60mL of water, and the lower layer is 40mL of colloidal liquid
Oil repellency	50mL of upper oil and 50mL of lower gel

3. Experiment for resisting high temperature and potassium formate pollution of completion fluid and oil-based drilling fluid

Testing fluidity and hydrophobicity after aging at different temperatures; and respectively carrying out pollution experiments on the potassium formate completion fluid, the oil-based drilling fluid and the gel spacer fluid according to different proportions.

The specific method comprises the following steps:

high temperature resistance: and aging at 120 deg.C, 150 deg.C and 180 deg.C for 16 hr, and testing fluidity and hydrophobicity of the gel spacer.

Pollution of potassium formate completion fluid and oil-based drilling fluid: after the gel isolation liquid and the potassium formate completion liquid are uniformly stirred by a stirrer (stirring for 5 min) according to the following ratio of 7,5,3.

The above experiments were repeated using an oil-based drilling fluid in place of the potassium formate completion fluid.

The test results are as follows:

(1) The high temperature resistance test data are as follows:

(2) The potassium formate completion fluid contamination test data is as follows:

(3) The oil-based drilling fluid contamination test data is as follows:

in conclusion, the invention has better hydrophobic and oleophobic performances; at the temperature of 150 ℃ and 180 ℃, the viscosity is reduced, the high temperature resistance is general, the pollution resistance is good, and the serious sedimentation or precipitation of the drilling fluid is not influenced or the drilling fluid is seriously thickened to lose the fluidity.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention. The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, it should be noted that any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (4)

1. The gel spacer fluid for the oil and gas fields is characterized in that: comprises the following raw materials by weight and 100 percent, wherein, the modified vegetable gum accounts for 20 to 25 percent, the flow pattern regulator accounts for 3 to 6 percent, the N-diethylaniline accounts for 0.1 to 0.4 percent, and the balance is water;

wherein, the modified vegetable gum is prepared by uniformly mixing 0.1 to 0.6 part of xanthan gum, 0.04 to 0.3 part of guar gum, 0.2 to 0.6 part of sesbania gum, 0.1 to 1.2 parts of fenugreek gum, 0.01 to 0.15 part of konjac gum and 0.01 to 0.2 part of locust bean gum;

wherein, the flow pattern regulator is prepared by polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1-2;

the modified vegetable gum adopts natural polysaccharide high molecular compounds, has better water solubility and cross-linking property, and has higher viscosity; under the action of polymeric alcohol, carboxymethyl cellulose, hydroxymethyl cellulose and N-diethylaniline, the modified vegetable gum can better form a gum system with the aqueous solution; the viscosity of the product is better, and the high temperature resistance of the product is improved;

the preparation method comprises the following steps: step 1: weighing the component materials according to the formula ratio, and respectively and fully mixing the component materials uniformly according to the proportion;

step 2: taking the water in the formula, placing the water in a preparation container, and heating the water to 35-40 ℃;

and step 3: adding flow pattern regulator and N-diethylaniline, stirring for 10-15min to fully mix the flow pattern regulator and the N-diethylaniline with water;

and 4, step 4: slowly adding the modified vegetable gum into a preparation container, slowly stirring for 1-3min at a speed of 20-40r/min, and after stirring is finished, increasing the rotation speed to 60-80r/min, and stirring for 20-30min to obtain a gel isolation solution;

wherein, in the step 2, the formula water is taken and then placed in a preparation container, and the water is heated to 38 ℃;

and 4, slowly adding the modified vegetable gum into the preparation container, slowly stirring for 2min at the speed of 30r/min, and after stirring is finished, increasing the rotating speed to 70r/min and stirring for 25min.

2. The gel spacer fluid for oil and gas fields as claimed in claim 1, wherein: 20% of modified vegetable gum, 3% of flow pattern regulator, 0.1% of N-diethylaniline and the balance of water;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.1 part of xanthan gum, 0.04 part of guar gum, 0.2 part of sesbania gum, 0.1 part of fenugreek gum, 0.01 part of konjac glucomannan and 0.01 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 1.

3. The gel spacer fluid for oil and gas fields as claimed in claim 1, wherein: 23% of modified vegetable gum, 5% of flow pattern regulator, 0.3% of N-diethylaniline and the balance of water;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.4 part of xanthan gum, 0.2 part of guar gum, 0.4 part of sesbania gum, 0.8 part of fenugreek gum, 0.1 part of konjac glucomannan and 0.15 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 2.8.

4. The gel spacer fluid for oil and gas fields as claimed in claim 1, wherein: 25% of modified vegetable gum, 6% of flow pattern regulator, 0.4% of N-diethylaniline and the balance of water;

wherein, the modified vegetable gum is mainly prepared by uniformly mixing 0.6 part of xanthan gum, 0.3 part of guar gum, 0.6 part of sesbania gum, 1.2 parts of fenugreek gum, 0.15 part of konjac glucomannan and 0.2 part of locust bean gum;

wherein, the flow pattern regulator is prepared from polyalcohol, carboxymethyl cellulose and hydroxymethyl cellulose according to the weight ratio of 2.