Jam freeing agent for drilling fluid and preparation process of jam freeing agent

Abstract

The invention belongs to the technical field of petroleum drilling, and particularly relates to a sticking freeing agent for drilling fluid and a preparation technology thereof.The sticking freeing agent comprises, by mass, 80% of a first sticking freeing agent and 20% of a second sticking freeing agent; the first jam freeing agent comprises the following components: a main agent: 50%-65% of polyoxyethylene ether; an auxiliary agent: 6%-8% of lauryl alcohol; a solvent: 6%-11% of propylene glycol; a gel breaker: 0.05%-0.2% of hydrogen peroxide; a demulsifying agent: 0.05%-0.2% of polyoxyethylene alkyl cresol ether; and the balance of water. And the second jam freeing agent comprises polyoxyethylene balls. According to the scheme, the problems that the decomposition capacity is reduced due to excessive polyoxyethylene ether and the permeability is poor due to too little polyoxyethylene ether are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum drilling, and in particular relates to a de-stuck agent for drilling fluid and a preparation process thereof. Background Art

[0002] During the drilling process, due to geological and drilling fluid properties and operational reasons, the drill bit may get stuck in the wellbore. Liquid is used to release the sticking point. This liquid is called a release agent, and its purpose is to release the drill bit from the wellbore.

[0003] At present, the existing announcement number is CN101328402A, which is an oil well unblocking and unstuck agent and its preparation method, which is used in oil field oil wells to remove well stuck accidents caused by scale deposition. The characteristics are: the weight ratio of each component is: a. nonylphenol polyoxyethylene ether NPD-100: 5.5-8%; b. nonylphenol polyoxyethylene ether NPD-200: 10-15%; c. hydrochloric acid: 2.0-3.5%; d. methanol: 20-25%; e. INTECHEM-02 fluorocarbon surfactant: 0.05-0.2%; f. the rest is water. The effect is: using 0.5%-1% of the unblocking and unstuck agent aqueous solution to flush the oil well at a large displacement, the well stuck accident caused by scale deposition is removed, the pump inspection cycle is extended, the oil well pump inspection cost is reduced, and the oil production cost is reduced.

[0004] However, there is also a problem: the content of polyoxyethylene ether used in the card release agent is relatively low, although it can ensure the decomposition performance, the hydrophilic permeability will be reduced. Excessive polyoxyethylene ether is easy to occupy the attachment point, resulting in a decrease in decomposition ability. Summary of the invention

[0005] The present invention provides a drilling fluid deblocking agent, which is used to solve the problem that excessive polyoxyethylene ether leads to reduced decomposition ability and too little polyoxyethylene ether leads to poor permeability.

[0006] The present invention provides a drilling fluid de-stuck agent, comprising the following components in mass percentage: a first de-stuck agent and a second de-stuck agent, wherein the mass percentage of the first de-stuck agent is 80%, and the mass percentage of the second de-stuck agent is 20%; the first de-stuck agent comprises: a main agent: polyoxyethylene ether: 50%-65%; an auxiliary agent: lauryl alcohol: 6%-8%; a solvent: propylene glycol: 6%-11%; a breaker: hydrogen peroxide: 0.05%-0.2%; a demulsifier: polyoxyethylene alkyl cresol ether 0.05%-0.2%; and the balance is water; the second de-stuck agent comprises: polyoxyethylene balls.

[0007] The principle of this scheme is that the polyoxyethylene solid is insoluble in propylene glycol and hydrogen peroxide and can remain solid in the solution. When the deblocking agent is put into the well, the polyoxyethylene ether will wet the surface of the oil cake and dissolve the hydrophilic substance at the same time, and then the lauryl alcohol can better penetrate into the oil cake to dissolve the organic matter hidden inside, and at the same time allow hydrogen peroxide to enter the interior, hydrogen peroxide will decompose the organic matter, and the polyoxyethylene alkyl cresol ether acts as a demulsifier to destroy the emulsion in the mud cake or the surrounding environment and reduce its viscosity.

[0008] When the inside of the oil cake is almost decomposed, at this time, under the action of the high temperature at the bottom of the well, the polyoxyethylene balls begin to react with propylene glycol to produce polyoxyethylene ether, which increases the mass percentage of the remaining substances of the polyoxyethylene ether, allowing the polyoxyethylene ether to continue to penetrate outward and then decompose.

[0009] The beneficial effect of this solution is that the polyoxyethylene spheres do not need to have a high initial polyoxyethylene ether mass percentage, which is only used to wet the surface and increase fluidity. When lauryl alcohol enters the interior to dissolve the organic matter, the polyoxyethylene spheres react with propylene glycol at this time. As the solvent propylene glycol decreases, the solvent mass percentage decreases, which increases the content of polyoxyethylene ether and other solvents, and performs penetration decomposition again. This solution greatly improves efficiency.

[0010] The existing method generally adopts multi-stage addition, and the amount of propylene glycol solvent cannot be too low, which easily leads to an excessively high mass percentage of internal hydrogen peroxide, resulting in pipeline corrosion, and multi-stage addition is very troublesome and costly. This solution consumes propylene glycol through polyoxyethylene balls. On the one hand, it avoids the initial excessively high mass percentage of polyoxyethylene ether which will lead to a decrease in the attachment point of lauryl alcohol. On the other hand, the polyoxyethylene balls are used to subsequently supplement polyoxyethylene ether to ensure its permeability. At the same time, the reduction of propylene glycol can increase the mass percentage of the remaining components and enhance the corrosion effect.

[0011] Furthermore, a sulfuric acid solution is provided in the polyoxyethylene ball, and the mass percentage of sulfuric acid in the sulfuric acid solution is 90%. Putting sulfuric acid in the polyoxyethylene ball can, on the one hand, make the polyoxyethylene react more quickly under strong acid conditions such as sulfuric acid, and on the other hand, sulfuric acid can improve the decomposition ability. Compared with adding sulfuric acid directly to the solution, this can prevent sulfuric acid from corroding the drilling pipe.

[0012] Furthermore, the mass percentage of the polyoxyethylene ether is 60%. 60% of the polyoxyethylene ether has the best permeability without interfering with the effect of lauryl alcohol.

[0013] Furthermore, the mass percentage of the propylene glycol is 10%. 10% of propylene glycol can ensure that substances such as polyoxyethylene ether are dissolved in the propylene glycol, thereby preventing some substances from precipitating out.

[0014] A process for preparing a drilling fluid de-stuck agent comprises the following steps:

[0015] Step S10: stirring and mixing polyoxyethylene ether and propylene glycol, and heating to a set temperature;

[0016] Step S20: adding lauryl alcohol, increasing the pressure to a set pressure, and then continuing stirring for a set time, then stopping stirring and releasing the pressure to normal pressure;

[0017] Step S30: stirring and cooling to below the set temperature, adding hydrogen peroxide and polyoxyethylene alkyl cresol ether, and continuing stirring and cooling to room temperature;

[0018] Step S40: inject sulfuric acid into the polyoxyethylene spheres, and then place the polyoxyethylene spheres into the solution.

[0019] This process can mix the various substances together very well.

[0020] Furthermore, in step S10, the temperature is raised to 80-90°C.

[0021] Furthermore, in step S20, the pressure is increased to 0.4-0.7 MPa, and then stirred for 1.5 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a graph showing the mass percentage change of polyoxyethylene ether, a drilling fluid deblocking agent.

[0023] Figure 2 This is a graph showing the mass percentage of polyoxyethylene ether and lauryl alcohol and the permeability of a drilling fluid de-blocking agent, which is 30% by mass.

[0024] Figure 3 This is a graph showing the mass percentage of polyoxyethylene ether and lauryl alcohol and the permeability of a drilling fluid de-blocking agent, which is 60% by mass.

[0025] Figure 4 The diagram is a graph showing the mass percentage of polyoxyethylene ether, a drilling fluid de-stuck agent, and the mass percentage of ether lauryl alcohol and the permeability thereof, which is 80%. DETAILED DESCRIPTION

[0026] Basically as attached Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown:

[0027] The present invention also provides a process for preparing a drilling fluid de-stuck agent, comprising the following steps:

[0028] Step S10: stirring and mixing polyoxyethylene ether X and propylene glycol Y, and heating to 80° C.;

[0029] Step S20: adding lauryl alcohol Z, raising the pressure to 0.6 MPa, and continuing stirring for 1.5 hours, then stopping stirring and releasing the pressure to normal pressure;

[0030] Step S30: stirring and cooling to a setting temperature below 70° C., adding hydrogen peroxide M and polyoxyethylene alkyl cresol ether N, and continuing stirring and cooling to room temperature;

[0031] Step S40: injecting sulfuric acid F into the polyethylene oxide ball H;

[0032] Step S50: Covering the surface of the polyoxyethylene ball H with a layer of carbon film G, and then placing the polyoxyethylene ball H into the solution.

[0033] This process can mix the various substances together very well and at the same time can bring out the maximum effect of each substance. During the preparation process, heating to 80°C for stirring can accelerate the integration of polyoxyethylene ether into propylene glycol and improve the preparation efficiency. Increasing the pressure to 0.6MPa can ensure that lauryl alcohol can be fully dissolved and evenly dispersed in the reaction system, as well as improve the reaction efficiency. The solubility of lauryl alcohol in the solvent can be increased, making it easier to dissolve. Cooling to below 70°C in step S30 is to prevent hydrogen peroxide from decomposing due to heat.

[0034] The specific mass percentages of various substances are shown in Table 1 below:

[0035]

[0036] Table 2: Decomposition and penetration capabilities of various substances:

[0037]

[0038] The intensity is 1, the gradient is the strongest, 7, the gradient is the weakest, and it gradually weakens from 1 to 7. As can be seen from Tables 1 and 2, the higher the mass percentage of polyoxyethylene ether, the better the penetration effect, but too high a mass percentage will lead to a decrease in decomposition ability, and too low a mass percentage will also lead to a decrease in decomposition ability. Therefore, when the mass percentage of polyoxyethylene ether is 60%, the effect is the best. After adding polyoxyethylene balls, the decomposition ability and penetration distance of the card release agent have been improved. The decomposition and penetration of polyoxyethylene balls containing concentrated sulfuric acid are stronger than those without concentrated sulfuric acid. At the same time, the decomposition and penetration of polyoxyethylene balls covered with carbon film are stronger than those without carbon film.

[0039] It can be seen that Example 4 is the best solution. This solution provides a drilling fluid de-stuck agent, including the following components in mass percentage: the first de-stuck agent accounts for 80%, and the first de-stuck agent includes: main agent: polyoxyethylene ether: 60%; auxiliary agent: lauryl alcohol: 7%; solvent: propylene glycol: 10%; breaker: hydrogen peroxide: 0.15%; demulsifier: polyoxyethylene alkyl cresol ether: 0.15%, and the balance is water.

[0040] The second deblocking agent includes polyoxyethylene balls, accounting for 20%; the polyoxyethylene balls contain 90% by mass of sulfuric acid solution, the solvent is water, and the surface of the polyoxyethylene balls is covered with a carbon film.

[0041] The principle of this scheme is that the polyoxyethylene solid is insoluble in propylene glycol and hydrogen peroxide and can remain solid in the solution. When the deblocking agent is put into the well, the polyoxyethylene ether will wet the surface of the oil cake and dissolve the hydrophilic substance at the same time, and then the lauryl alcohol can better penetrate into the oil cake to dissolve the organic matter hidden inside, and at the same time allow hydrogen peroxide to enter the interior, hydrogen peroxide will decompose the organic matter, and the polyoxyethylene alkyl cresol ether acts as a demulsifier to destroy the emulsion in the mud cake or the surrounding environment and reduce its viscosity.

[0042] When the oil cake is almost decomposed, the polyoxyethylene balls begin to react with propylene glycol under the catalysis of sulfuric acid under the high temperature at the bottom of the well. The reaction formula is:

[0043] H-(CH2CH2O) n -OH+CH3CH(OH)CH2OH→CH3CH(OH)CH2O-(CH2CH2O) n -OH+H2O,

[0044] Where: H-(CH2CH2O) n -OH is polyoxyethylene (PEO); CH3CH(OH)CH2OH is propylene glycol, CH3CH(OH)CH2O-(CH2CH2O) n -OH is polyoxyethylene ether, and H20 is water. The generation of polyoxyethylene ether increases the mass percentage of the remaining substances of polyoxyethylene ether, allowing the polyoxyethylene ether to continue to permeate outwards. At the same time, the remaining concentrated sulfuric acid will enhance the decomposition ability of the deblocking agent, and then decompose.

[0045] Polyoxyethylene balls can easily generate polyoxyethylene ether solution under the catalysis of concentrated sulfuric acid at high temperature. If the polyoxyethylene balls are reacted before reaching the set position at this time, it is easy to form a hole, causing the internal concentrated sulfuric acid to flow out, resulting in corrosion of the drill bit and drill rod. At the same time, along with the loss of concentrated sulfuric acid, other unreacted polyoxyethylene balls are difficult to react into polyoxyethylene ether without the action of a catalyst, resulting in the ultimate failure to achieve the desired effect.

[0046] This solution wraps a layer of carbon film on the surface of the polyoxyethylene ball. At high temperature, concentrated sulfuric acid can slowly oxidize carbon to generate carbon dioxide and water: the carbon film plays a role in preventing the leakage of concentrated sulfuric acid. When the polyoxyethylene ball partially reacts, the concentrated sulfuric acid will flow out, which will also be blocked by the carbon film, so that the concentrated sulfuric acid still acts as a catalyst inside the polyoxyethylene ball. When the polyoxyethylene ball reacts completely, the concentrated sulfuric acid will slowly react with the carbon film, causing the concentrated sulfuric acid to flow out.

[0047] The beneficial effects of this solution are as follows: 1. This solution uses polyoxyethylene balls so that the initial polyoxyethylene ether mass percentage does not need to be too high, and is only used to wet the surface and increase fluidity. When lauryl alcohol enters the interior to dissolve the organic matter, the polyoxyethylene balls react with propylene glycol at this time to reduce the solvent, increase the content of polyoxyethylene ether and other solvents, and perform penetration decomposition again. This solution greatly improves efficiency. 2. This solution ensures the complete reaction of the polyoxyethylene balls, and at the same time prevents concentrated sulfuric acid from flowing out prematurely, causing equipment damage.

[0048] The existing method generally adopts multi-stage addition, and the amount of propylene glycol solvent cannot be too low, which easily leads to an excessively high mass percentage of internal hydrogen peroxide, resulting in pipeline corrosion, and multi-stage addition is very troublesome and costly. This solution consumes propylene glycol through polyoxyethylene balls. On the one hand, it avoids the initial excessively high mass percentage of polyoxyethylene ether which will lead to a decrease in the attachment point of lauryl alcohol. On the other hand, the polyoxyethylene balls are used to subsequently supplement polyoxyethylene ether to ensure its permeability. At the same time, the reduction of propylene glycol can increase the mass percentage of the remaining components and enhance the corrosion effect.

[0049] The above are only embodiments of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A drilling fluid de-stuck agent, characterized in that: Includes the following mass percentage components: The first jam-releasing agent and the second jam-releasing agent, the first jam-releasing agent has a mass percentage of 80%, and the second jam-releasing agent has a mass percentage of 20%; the first jam-releasing agent includes: Main agent: polyoxyethylene ether: 50%-65%; Auxiliary agents: lauryl alcohol: 6%-8%; Solvent: Propylene glycol: 6%-11%; Gel breaker: Hydrogen peroxide: 0.05%-0.2%; Demulsifier: polyoxyethylene alkyl cresol ether 0.05%-0.2%; The balance is water; The second deblocking agent includes: polyethylene oxide balls.

2. A drilling fluid de-stuck agent according to claim 1, characterized in that: A sulfuric acid solution is provided in the polyoxyethylene ball, and the mass percentage of sulfuric acid in the sulfuric acid solution is 90%.

3. A drilling fluid de-stuck agent according to claim 2, characterized in that: The mass percentage of the polyoxyethylene ether is 60%.

4. A drilling fluid de-stuck agent according to claim 2, characterized in that: The mass percentage of the propylene glycol is 10%.

5. A process for preparing a drilling fluid de-stuck agent, characterized in that: The following steps are involved: step S10: Stir and mix the polyoxyethylene ether and propylene glycol, and heat to a set temperature; Step S20: adding lauryl alcohol, increasing the pressure to a set pressure, and then continuing stirring for a set time, then stopping stirring and releasing the pressure to normal pressure; Step S30: stirring and cooling to below the set temperature, adding hydrogen peroxide and polyoxyethylene alkyl cresol ether, and continuing stirring and cooling to room temperature; Step S40: inject sulfuric acid into the polyoxyethylene spheres, and then place the polyoxyethylene spheres into the solution.

6. A process for preparing a drilling fluid de-stuck agent according to claim 5, characterized in that: In step S10, the temperature is raised to 80-90°C.

7. The process for preparing a drilling fluid de-stuck agent according to claim 5, characterized in that: In the step S20, the pressure is increased to 0.4-0.7 MPa, and then stirred for 1.5 hours.

Images