阅读说明：本技术 一种固体防蜡剂防止凝析气井结蜡的方法 (Method for preventing condensate gas well from waxing by using solid wax inhibitor ) 是由 刘己全 杨向同 王茜 孙涛 钟诚 张晖 黎真 唐胜蓝 姚茂堂 孟繁印 于 2018-06-12 设计创作，主要内容包括：本发明提供一种固体防蜡剂防止凝析气井结蜡的方法,依序包括如下步骤：向所述凝析气井注入酸液进行第一处理；所述第一处理结束后,向所述凝析气井注入压裂防蜡混合物进行第二处理；所述第二处理结束后,焖井；其中,所述压裂防蜡混合物是压裂液、支撑剂与固体防蜡剂的混合物。该方法使凝析气从地层流到井底过程中就可以与固体防蜡剂进行接触并反应,从而降低凝析气在井筒流动期间的析蜡点,可有效缓解凝析气井在开采过程中由于温度和压力的降低而导致的结蜡问题,并可实现长效防蜡。(The invention provides a method for preventing a condensate gas well from waxing by using a solid wax inhibitor, which sequentially comprises the following steps: injecting acid liquor into the condensate gas well for first treatment; after the first treatment is finished, injecting a fracturing wax-proofing mixture into the condensate gas well for second treatment; after the second treatment is finished, soaking the well; wherein the fracturing wax-proofing mixture is a mixture of fracturing fluid, proppant and solid wax-proofing agent. The method enables the condensate gas to contact and react with the solid paraffin inhibitor in the process of flowing from the ground to the bottom of the well, thereby reducing the paraffin point of the condensate gas in the flowing period of the shaft, effectively relieving the problem of paraffin precipitation caused by the reduction of temperature and pressure in the exploitation process of the condensate gas well, and realizing long-term paraffin control.)

1. A method for preventing the wax deposition of a condensate gas well by using a solid wax inhibitor is characterized by sequentially comprising the following steps:

injecting acid liquor into the condensate gas well for first treatment;

injecting a fracturing wax-proofing mixture into the condensate gas well for second treatment;

stewing;

wherein the fracturing wax-proofing mixture is a mixture of fracturing fluid, proppant and solid wax-proofing agent.

2. The method of claim 1 further comprising, prior to injecting the fracturing paraffin control mixture into the gas condensate well:

and injecting a pad fluid into the condensate gas well.

3. The method of claim 2, wherein after injecting the fracturing paraffin control mixture into the gas condensate well, further comprising: and injecting a post fluid into the condensate gas well.

4. The method of claim 3, further comprising, after the soaking: and performing acid liquor flowback treatment on the condensate gas well.

5. The method as claimed in any one of claims 1 to 3, wherein the mass ratio of the fracturing fluid, the proppant and the solid wax-proofing agent in the fracturing wax-proofing mixture is (500- & 2000): (50-100): 1.

6. the method according to claim 5, wherein the acid solution comprises the following components in parts by mass: 8% hydrochloric acid, 2% hydrofluoric acid, 2% clay stabilizer, 3.2% corrosion inhibitor, 1% cleanup additive, 0.2% drag reducer, 1% demulsifier and the balance water.

7. The method of claim 6, wherein the fracturing fluid comprises the following components in percentage by mass: 0.4 percent of guar gum, 20 percent of KCl, 1.0 percent of cleanup additive, 0.8 percent of demulsifier, 0.1 percent of bactericide, 0.2 percent of cross-linking agent and the balance of water.

8. The method of claim 7, wherein the proppant is a 30-50 mesh ceramsite.

9. The method according to claim 8, wherein the pad fluid comprises the following components in percentage by mass: 0.1% drag reducer, 1% cleanup additive, 0.8% demulsifier and the balance water.

10. The method of claim 9, wherein the post fluid is a mixture of the pre fluid and water, wherein the mass ratio of the pre fluid to the water is 1: 1.

Technical Field

The invention relates to a technology for preventing a condensate gas well from waxing, in particular to a method for preventing the condensate gas well from waxing by using a solid wax inhibitor, and belongs to the technical field of oil and gas exploitation.

Background

In the depletion production process of the condensate gas well, the temperature and pressure of the stratum can be continuously reduced along with the exploitation of the condensate gas, so that the phenomenon of wax deposition of the high-temperature and high-pressure condensate gas well is increasingly common. The wax precipitation can reduce the gas flow channel of the condensate gas, increase the flow resistance, and if the wax is not removed in time, the tubular column can be blocked or even completely blocked, the underground safety valve fails, the oil sleeve is communicated, and the integrity risk exists. For condensate gas wells with wax deposition in the shaft, multiple times of hot washing operation are generally adopted, and the wells are repeatedly opened and closed, so that the operation measure is low in efficiency and high in cost.

In 2016, a paper, namely exploration and application of a low-permeability oilfield paraffin removal and prevention mode, published in technical crossbar 35, volume 7, proposes that a solid paraffin inhibitor can effectively relieve the paraffin precipitation phenomenon of an oil well, but the solid paraffin inhibitor generally has the problems of short effective period, increased operation times and viscosity reduction cost, and cannot meet the paraffin inhibition requirement in a high-temperature and high-pressure condensate gas well. In the paper published in the petrochemical engineering application 32, volume 6, of 2013, the Changqing white leopard oil field solid paraffin control technology research enables the load of an oil pumping unit to be obviously reduced compared with that before a solid paraffin control agent is reinforced, the paraffin removal and control operation is effectively reduced, the pump detection period is prolonged, and the paraffin control requirement in a high-temperature and high-pressure condensate gas well cannot be met.

The solid paraffin inhibitor is mainly used for oil wells as a paraffin removal and prevention measure, the application of the solid paraffin inhibitor of the condensate gas well is relatively few at present, if the solid paraffin inhibitor can be used for realizing long-acting paraffin prevention of the condensate gas well, the solid paraffin inhibitor is an economical and practical measure, but at present, no technological method for preventing the condensate gas well from being waxed by the solid paraffin inhibitor is provided at home.

Disclosure of Invention

In view of the above-mentioned defects, the present invention provides a method for preventing the wax deposition of a gas condensate well by using a solid wax inhibitor, which enables the condensate gas to contact and react with the solid wax inhibitor in the process of flowing from the ground to the bottom of the well, thereby reducing the wax deposition point of the condensate gas in the flowing period of a well bore, effectively relieving the wax deposition problem of the gas condensate well caused by the reduction of temperature and pressure in the exploitation process, and realizing long-term wax control.

The invention provides a method for preventing a condensate gas well from waxing by using a solid wax inhibitor, which sequentially comprises the following steps:

injecting acid liquor into the condensate gas well for first treatment;

injecting a fracturing wax-proofing mixture into the condensate gas well for second treatment;

stewing;

wherein the fracturing wax-proofing mixture is a mixture of fracturing fluid, proppant and solid wax-proofing agent.

The method for preventing the wax precipitation of the condensate gas well by using the solid wax inhibitor is characterized by further comprising the following steps before injecting the fracturing wax-proofing mixture into the condensate gas well:

and injecting a pad fluid into the condensate gas well.

The method for preventing the paraffin precipitation of the condensate gas well by using the solid paraffin inhibitor comprises the following steps after injecting a fracturing paraffin inhibitor mixture into the condensate gas well: and injecting a post fluid into the condensate gas well.

The method for preventing the wax deposition of the condensate gas well by the solid wax inhibitor is characterized by further comprising the following steps after the well stewing: and performing acid liquor flowback treatment on the condensate gas well.

The method for preventing the paraffin precipitation of the condensate gas well by using the solid paraffin inhibitor is characterized in that in the fracturing paraffin inhibitor mixture, the mass ratio of the fracturing fluid to the proppant to the solid paraffin inhibitor is (500-2000): (50-100): 1.

the method for preventing the gas condensate well from waxing by using the solid paraffin inhibitor comprises the following components in parts by mass: 8% hydrochloric acid, 2% hydrofluoric acid, 2% clay stabilizer, 3.2% corrosion inhibitor, 1% cleanup additive, 0.2% drag reducer, 1% demulsifier and the balance water.

The method for preventing the paraffin precipitation of the gas condensate well by using the solid paraffin inhibitor comprises the following components in percentage by mass: 0.4 percent of guar gum, 20 percent of KCl, 1.0 percent of cleanup additive, 0.8 percent of demulsifier, 0.1 percent of bactericide, 0.2 percent of cross-linking agent and the balance of water.

The method for preventing the paraffin precipitation of the condensate gas well by using the solid paraffin inhibitor is characterized in that the proppant is a 30-50-mesh ceramsite.

The method for preventing the paraffin precipitation of the condensate gas well by using the solid paraffin inhibitor comprises the following components in percentage by mass: 0.1% drag reducer, 1% cleanup additive, 0.8% demulsifier and the balance water.

The method for preventing the paraffin precipitation of the gas condensate well by using the solid paraffin inhibitor is characterized in that the post-fluid is a mixture of the pre-fluid and water, wherein the mass ratio of the pre-fluid to the water is 1: 1.

the implementation of the invention has at least the following advantages:

1. according to the method for preventing the condensate gas well from waxing by using the solid paraffin inhibitor, in the process of exploiting the condensate gas, the condensate gas can contact and react with the solid paraffin inhibitor in the process of flowing from the ground to the bottom of the well, so that the wax precipitation point of the condensate gas in the flowing period of a shaft is reduced, and the problem of wax precipitation of the condensate gas well caused by the reduction of temperature and pressure in the exploiting process can be effectively solved;

2. in the method for preventing the paraffin precipitation of the condensate gas well by using the solid paraffin inhibitor, the solid paraffin inhibitor can enter the stratum and is in the stratum for a long time, so that long-acting paraffin inhibition can be realized, and the paraffin inhibition efficiency is effectively improved;

3. the method for preventing the condensate gas well from waxing by using the solid paraffin inhibitor further performs acid fracturing modification construction on the condensate gas well, can relieve and break through near-well reservoir pollution, communicate, extend and dredge a natural fracture system, and improve the yield of the condensate gas well.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a flow chart of an embodiment of a method of the present invention for preventing wax deposition in a gas condensate well;

FIG. 2 is a flow chart of another embodiment of the method of the present invention for preventing wax deposition in a gas condensate well;

FIG. 3 is a flow chart of yet another embodiment of the method of the present invention for preventing waxing of a gas condensate well;

FIG. 4 is a flow chart of another embodiment of a method of the present invention for preventing waxing of a gas condensate well;

fig. 5 is a schematic structural diagram of equipment for producing a condensate gas well according to an embodiment 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present 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.

The condensate comprisingThe main elements include carbon, hydrogen, nitrogen, oxygen, sulfur and trace metal elements such as vanadium, nickel, iron, copper and the like. Mainly exists in the form of hydrocarbon and accounts for more than 75 percent of the condensate gas. The wax precipitated in condensate wells is C₁₆-C₆₄And paraffins, i.e. paraffins. Meanwhile, the wax in the condensate gas well is formed by mixing colloid, asphaltene, oil and paraffin.

The solubility of paraffin in condensate decreases with decreasing temperature. Before the development of condensate wells, the wax in the condensate was completely dissolved in the condensate. In the process of exploiting the condensate gas well, condensate gas flows into the bottom of the well from a stratum, and then rises to a well head from the bottom of the well along a shaft, the pressure and the temperature gradually drop, when the pressure is reduced to a certain degree, light components which are beneficial to dissolving paraffin and colloid are gradually lost, and as a result, the equilibrium condition of paraffin dissolution is destroyed, and at the moment, the saturation degree of paraffin in the condensate gas is exceeded, so that the paraffin is crystallized, precipitated, condensed and adhered to the surface of an exploitation facility, namely paraffin precipitation.

The paraffin precipitation is a problem frequently encountered in the process of exploitation, and particularly when high-wax-content condensate gas is exploited, the paraffin is precipitated and continuously deposited on the pipe wall of an oil pipe, underground equipment such as a sucker rod and an oil well pump, and metal surfaces of ground technical pipelines, valves, separators, storage tanks and the like, so that the flow area of crude oil is reduced, the flow resistance of the crude oil is increased, and the production is reduced as a result. When the wax deposition is serious, the oil well pipeline can be completely blocked, and the production is stopped. Therefore, wax control is one of the most important measures in oil well management.