CN105567212A - Reusable modified guar gum fracturing fluid system - Google Patents

Abstract

The invention relates to a reusable modified guar gum fracturing fluid system. According to the technical scheme, the system comprises a primary mixed solution and a secondary mixed solution, wherein chemicals of a reusable fracturing system are adopted as the primary mixed solution and include compound modified guar gum, an organo-boron cross-linking agent, a low-temperature activator, a cleanup activator, a gel breaker removal adhesion preserving agent, an ionic equilibrium regulator, a molecular remodeling carding agent and a gel breaker. The base fluid formula of the secondary mixed solution includes an antibacterial agent formaldehyde, a gel breaker removal adhesion preserving agent, an ionic equilibrium regulator, thickening agent guar gum and a cleanup activator. The system has the advantages that the problems about water lack and environmental protection pressure during oilfield development in dry and rainless regions are solved, and secondary utilization of flowback fluid of fracturing fluid is achieved. On the premise that the requirements for safe fracturing construction and reservoir protection are met, fracturing fluid is easy to maintain and process and can be repeatedly used, the treatment amount of the flowback fluid is reduced, and water resources are saved.

Description

One can reuse modified guar fracturing fluid system

Technical field

The present invention relates to a kind of fracturing liquid recycling technology of field produces, particularly one can reuse modified guar fracturing fluid system.

Background technology

Along with the quickening of large-scale development of China's western region rhythm, the exploitation of western oil-gas field also enters the stage of great development, the benefit brought of great development and western part crisp fall environment form sharp contrast, also have western part of China drought, water resources is anxious to be lacked, and mountain region is many seriously limits further developing of oil-gas field.

For Ju Weibei oil field, China Petrochemical Industry North China, Wei Bei oil field block is positioned at Loess Plateau of North Shaanxi, the height above sea level discrepancy in elevation reaches 300m, average temperature of the whole year 8.9 DEG C, mean annual precipitation 709.3mm, has inconvenient traffic, and winter-spring season temperature is on the low side, shortage of water resources and skewness, reservoir reconstruction construction water and to return discharge opeing intractability large.This district's oil reservoir belongs to the lithologic oil pool of an ultra shallow floor low-temp low-pressure tight sand in addition, and breaking glue low temperature to the reservoir protection performance of entry well fluid and fracturing liquid low temperature, to break glue performance requriements higher.

Wei Bei oil field is developed efficiently to realize economy of large scale; need to continue to carry out Low Damage, low cost development Study on Process; comprising to protect reservoir, saving water resource, minimizing oilfield chemical auxiliary consumption, shorten construction period, to protect recyclable fracturing liquid research and development for the purpose of oily district environment and application technical research; to advance the oil field Sustainable Exploitation process of cost efficiency, environmental protection, completing smoothly of boosting Productivity Construction target.Carry out and can research and develop and reuse technology research by reuse fracturing liquid auxiliary agent, form fracturing outlet liquid to reclaim, process and reutilization technology system, effectively can alleviate the situation of fracturing liquid for water difficulty, shorten construction period, reduce water resource waste, the consumption of partial open liquid material can also be reduced because of reuse.

The comprehensive analysis domestic and international fracturing liquid recycling state of the art is known, although explore many in the recycling of different fracturing fluid system, but still there are crucial technological difficulties, constrain applying of this technology, induction and conclusion is 3 points:

1, hydroxypropyl guar gum pressure break system recycling difficulty is large

Current oil field at home mainly uses conventional water base hydropropyl guar fracturing fluid system, and affect by molecular structure, crosslinked and broken glue mode, the useful component that after pressing crack construction, broken glue returns in discharge opeing not easily retains recycling, and site disposal recovery difficult is large.

2, discharge opeing reuse level is returned secondary low

Return the overlaying influence that discharge opeing exists local water, crude oil and other objectionable constituent, return discharge opeing recycling number of times higher, return discharge opeing treatment and reuse difficulty larger.Under the prerequisite taking into account economy and technical feasibility, current domestic fracturing outlet liquid recycling rests on the second stage employ stage substantially, and reuse economic benefit is fully excavated.Therefore, fracturing liquid reuse technology needs to carry out the strong Processing Technology Research of low cost, forms the fracturing liquid reuse technology system with oil reservoir specific aim, technical feasibility, economic validity.

3, discharge opeing recovery utilization rate is returned low

Fracturing outlet liquid complicated components, be harmful to useful component and deposit, being subject to processing technical limitation, at present the general only recovery liquid of the row's of returning early stage based on breaking glue solution, when local water or crude production rate proportion too high time processing costs increase severely, no longer have recycle be worth.At present except slippery water system, majority returns discharge opeing recovery utilization rate between 20-25%, and after pressure break, oil, aquatic products go out more early, or formation water salinity is higher, returns discharge opeing recovery utilization rate lower.

Current domestic pressure break has become the key link of Low permeable oil and gas reservoirs exploratory development, well time and scale increase year by year, fracturing liquid consumption and return lifting rate and also increase thereupon, water resource waste and environmental pollution are deeply concerned, tradition returns discharge opeing treatment process can not meet Green Development demand, therefore fracturing liquid recycling technical study comes into one's own, and becomes the development trend of social development and fracturing technique progress.

Up to now, the As-Is analysis of the comprehensive recycling of fracturing liquid both at home and abroad research, does not form the fracturing outlet liquid recycling Technology of any one system maturation, carries out the demand that fracturing liquid recycling research is industry progress and development.

Summary of the invention

Object of the present invention is exactly in view of the foregoing defects the prior art has, there is provided one can reuse modified guar fracturing fluid system, in new system research, the molecular structure of viscosifying agent is redesigned, introduce better group more hydrophilic than hydroxypropyl, and improve reconstruct group ratio, improve swelling rate and the reconstruction property of viscosifying agent, and enhance the antibacterial ability of viscosifying agent; The preferred linking agent of applicable reuse system of research synthesis, solves the difficult problem that when using borax to be cross-linked, reuse rate of crosslinking is too fast, gelation time and gel-forming property requirement when making system meet reuse; Research optimizes gel breaking method further, solves the problem that reuse process breaks glue difficulty.

Its technical scheme comprises first dosing and secondary dosing, wherein adopt can the medicament of reuse pressure break system in first dosing, comprise composite modified guar 10-30 part, organic borate cross-linker 0.1-0.3 part, low-temp activation agent 0.1-0.3 part, the row of helping promoting agent 0.1-0.3 part, gel breaker removal guarantor stick 0.1-0.3 part, ionic equilibrium conditioning agent 0.1-0.3 part, Molecular remodeling carding agent 0.1-0.3 part, gel breaker 0.01-0.03 part.

The base fluid formula of described secondary dosing:

0.1% sterilant formaldehyde+0.05%-0.15% gel breaker is removed guarantor's stick+0.3-0.8% ionic equilibrium conditioning agent+0.30-0.25% viscosifying agent melon glue+0.05%-0.15% and is helped row's promoting agent;

Wherein, composite modified guar is two modified carboxy methyl hydroxypropyl guar rubber powders,

The row's of helping promoting agent is that 5% tensio-active agent and 10% organic solvent methyl alcohol are formulated,

Broken glue is removed and is protected the Sulfothiorine deionized water aqueous solution composition that stick is 5% mass percent,

In ionic equilibrium conditioning agent Main Function elimination breaking glue solution, metal ion is on the impact of secondary dosing, and its composition is 10% citric acid and 5% acetic acid mixed aqueous solution,

In Molecular remodeling carding agent effect elimination breaking glue solution, residual boron acid ion is on the impact of secondary plastic, and main component is the 30% borate ion complexing agent aluminum sulfate salt aqueous solution,

Low-temp activation agent is the triethanolamine solution of 30% massfraction; Gel breaker adopts ammonium persulphate.

Above-mentioned organic borate cross-linker is with sodium tetraborate, Xylitol, trolamine, glutaraldehyde, methyl alcohol, sodium hydroxide for main raw material(s), and through complex reaction, ph adjustment etc. is finally met the organic borate cross-linker of 140 DEG C of hot hole construction requirements; Its preparation method is: comprise the following steps, by weight:

(1), using 20% water add in reactor as solvent, then add 10% methyl alcohol stir be warmed up to 50 DEG C;

(2), in reactor drop into 15% sodium tetraborate, stir and keep 50 DEG C of constant temperature until sodium tetraborate dissolves completely;

(3), drop into 18% complexing agent Xylitol, stir and be warmed up to 60 DEG C, Xylitol fully dissolves;

(4), reactor closes lid sealing and continues to be warmed up to 75 DEG C, and keep constant temperature, drips the glutaraldehyde of 10% trolamine and 5% successively, is added dropwise to complete rear continuation constant temperature 75 DEG C reaction 3 hours;

(5) sodium hydroxide of the water dissolution 5%, with 17%, and suction drips in tank for subsequent use;

(6), by the sodium hydroxide solution in step (5) be added drop-wise in step (4), in dropping process, the moment pays close attention to the ph value change in reactor, then stops dripping after ph value to 10;

(7), continue to stir the change paying close attention to ph value in still, if ph reduces, the solution continuing to drip in step (5) is until drip in stopping after ph value stabilization;

(8), keep 75 DEG C of constant temperature to continue stirrings blowing after 1 hour, obtain high-temperature cross-linking agent.

The invention has the beneficial effects as follows: the lack of water faced when the invention solves the oil-field development of drought area and environmental protection pressure, realize the second stage employ of fracturing fluid recovery (backflow) liquid.Under the prerequisite meeting safe pressing crack construction and reservoir protection needs; realize the process of fracturing liquid simple-to-maintain, repeatedly use; reduce and return discharge opeing treatment capacity, saving water resource, shortening construction period, reduction material usage; reach the object of falling and originally subtracting expense and Efficient Development oil field; improve development benefit and safety and environmental protection usefulness; for the exploitation of oil-gas field economical and effective provides gordian technique guarantee, the increasing the storage of promotion low permeability oil field is produced.

Embodiment

Embodiment 1: what the present invention mentioned can reuse modified guar fracturing fluid system, comprise first dosing and secondary dosing, wherein adopt can the medicament of reuse pressure break system in first dosing, comprise composite modified guar 25 parts, organic borate cross-linker 0.2 part, low-temp activation agent 0.2 part, the row's of helping promoting agent 0.2 part, gel breaker removal guarantor stick 0.25 part, ionic equilibrium conditioning agent 0.27 part, Molecular remodeling carding agent 0.2 part, gel breaker 0.02 part.

The base fluid formula of described secondary dosing:

0.1% sterilant formaldehyde+0.05%-0.15% gel breaker is removed guarantor's stick+0.3-0.8% ionic equilibrium conditioning agent+0.30-0.25% viscosifying agent melon glue+0.05%-0.15% and is helped row's promoting agent;

Wherein, composite modified guar is two modified carboxy methyl hydroxypropyl guar rubber powders,

The row's of helping promoting agent is that 5% tensio-active agent and 10% organic solvent methyl alcohol are formulated,

Broken glue is removed and is protected the Sulfothiorine deionized water aqueous solution composition that stick is 5% mass percent,

In ionic equilibrium conditioning agent Main Function elimination breaking glue solution, metal ion is on the impact of secondary dosing, and its composition is 10% citric acid and 5% acetic acid mixed aqueous solution,

In Molecular remodeling carding agent effect elimination breaking glue solution, residual boron acid ion is on the impact of secondary plastic, and main component is the 30% borate ion complexing agent aluminum sulfate salt aqueous solution,

Low-temp activation agent is the triethanolamine solution of 30% massfraction; Gel breaker adopts ammonium persulphate.

Above-mentioned organic borate cross-linker is with sodium tetraborate, Xylitol, trolamine, glutaraldehyde, methyl alcohol, sodium hydroxide for main raw material(s), and through complex reaction, ph adjustment etc. is finally met the organic borate cross-linker of 140 DEG C of hot hole construction requirements; Its preparation method is: comprise the following steps, by weight:

(1), using 20% water add in reactor as solvent, then add 10% methyl alcohol stir be warmed up to 50 DEG C;

(2), in reactor drop into 15% sodium tetraborate, stir and keep 50 DEG C of constant temperature until sodium tetraborate dissolves completely;

(3), drop into 18% complexing agent Xylitol, stir and be warmed up to 60 DEG C, Xylitol fully dissolves;

(4), reactor closes lid sealing and continues to be warmed up to 75 DEG C, and keep constant temperature, drips the glutaraldehyde of 10% trolamine and 5% successively, is added dropwise to complete rear continuation constant temperature 75 DEG C reaction 3 hours;

(5) sodium hydroxide of the water dissolution 5%, with 17%, and suction drips in tank for subsequent use;

(6), by the sodium hydroxide solution in step (5) be added drop-wise in step (4), in dropping process, the moment pays close attention to the ph value change in reactor, then stops dripping after ph value to 10;

(7), continue to stir the change paying close attention to ph value in still, if ph reduces, the solution continuing to drip in step (5) is until drip in stopping after ph value stabilization;

(8), keep 75 DEG C of constant temperature to continue stirrings blowing after 1 hour, obtain high-temperature cross-linking agent.

Embodiment 2: what the present invention mentioned can reuse modified guar fracturing fluid system, difference from Example 1 is: wherein adopt can the medicament of reuse pressure break system in first dosing, comprise composite modified guar 10 parts, organic borate cross-linker 0.1 part, low-temp activation agent 0.1 part, the row's of helping promoting agent 0.1 part, gel breaker removal guarantor stick 0.1 part, ionic equilibrium conditioning agent 0.1 part, Molecular remodeling carding agent 0.1 part, gel breaker 0.01 part.

Embodiment 3: what the present invention mentioned can reuse modified guar fracturing fluid system, difference from Example 1 is: wherein adopt can the medicament of reuse pressure break system in first dosing, comprise composite modified guar 30 parts, organic borate cross-linker 0.3 part, low-temp activation agent 0.3 part, the row's of helping promoting agent 0.3 part, gel breaker removal guarantor stick 0.3 part, ionic equilibrium conditioning agent 0.3 part, Molecular remodeling carding agent 0.3 part, gel breaker 0.03 part.

What the present invention adopted can have good economic advantages by reuse fracturing fluid system, this system not only can produce larger economic benefit after applying, also can reduce fresh water dosage and sewage discharge, really accomplish the eco-friendly requirement of construction process, bring huge social benefit.

The above, be only part preferred embodiment of the present invention, any those of ordinary skill in the art all may utilize the technical scheme correct of above-mentioned elaboration or are revised as equivalent technical scheme.Therefore, any simple modification of carrying out according to technical scheme of the present invention or substitute equivalents, belong to the scope of protection of present invention to the greatest extent.

Claims (2)

1. one kind can reuse modified guar fracturing fluid system, it is characterized in that: comprise first dosing and secondary dosing, wherein adopt can the medicament of reuse pressure break system in first dosing, comprise composite modified guar 10-30 part, organic borate cross-linker 0.1-0.3 part, low-temp activation agent 0.1-0.3 part, the row of helping promoting agent 0.1-0.3 part, gel breaker removal guarantor stick 0.1-0.3 part, ionic equilibrium conditioning agent 0.1-0.3 part, Molecular remodeling carding agent 0.1-0.3 part, gel breaker 0.01-0.03 part;

The base fluid formula of described secondary dosing:

0.1% sterilant formaldehyde+0.05%-0.15% gel breaker is removed guarantor's stick+0.3-0.8% ionic equilibrium conditioning agent+0.30-0.25% viscosifying agent melon glue+0.05%-0.15% and is helped row's promoting agent;

Wherein, composite modified guar is two modified carboxy methyl hydroxypropyl guar rubber powders,

The row's of helping promoting agent is that 5% tensio-active agent and 10% organic solvent methyl alcohol are formulated,

Broken glue is removed and is protected the Sulfothiorine deionized water aqueous solution composition that stick is 5% mass percent,

In ionic equilibrium conditioning agent Main Function elimination breaking glue solution, metal ion is on the impact of secondary dosing, and its composition is 10% citric acid and 5% acetic acid mixed aqueous solution,

In Molecular remodeling carding agent effect elimination breaking glue solution, residual boron acid ion is on the impact of secondary plastic, and main component is the 30% borate ion complexing agent aluminum sulfate salt aqueous solution,

Low-temp activation agent is the triethanolamine solution of 30% massfraction; Gel breaker adopts ammonium persulphate.

2. according to claim 1 can reuse modified guar fracturing fluid system, it is characterized in that: described organic borate cross-linker with sodium tetraborate, Xylitol, trolamine, glutaraldehyde, methyl alcohol, sodium hydroxide for main raw material(s), through complex reaction, ph adjustment etc. is finally met the organic borate cross-linker of 140 DEG C of hot hole construction requirements; Its preparation method is:

Comprise the following steps, by weight:

(1), using 20% water add in reactor as solvent, then add 10% methyl alcohol stir be warmed up to 50 DEG C;

(2), in reactor drop into 15% sodium tetraborate, stir and keep 50 DEG C of constant temperature until sodium tetraborate dissolves completely;

(3), drop into 18% complexing agent Xylitol, stir and be warmed up to 60 DEG C, Xylitol fully dissolves;

(4), reactor closes lid sealing and continues to be warmed up to 75 DEG C, and keep constant temperature, drips the glutaraldehyde of 10% trolamine and 5% successively, is added dropwise to complete rear continuation constant temperature 75 DEG C reaction 3 hours;

(5) sodium hydroxide of the water dissolution 5%, with 17%, and suction drips in tank for subsequent use;

(6), by the sodium hydroxide solution in step (5) be added drop-wise in step (4), in dropping process, the moment pays close attention to the ph value change in reactor, then stops dripping after ph value to 10;

(7), continue to stir the change paying close attention to ph value in still, if ph reduces, the solution continuing to drip in step (5) is until drip in stopping after ph value stabilization;

(8), keep 75 DEG C of constant temperature to continue stirrings blowing after 1 hour, obtain high-temperature cross-linking agent.