阅读说明：本技术 稳定存放废弃钻井液的方法 (Method for stably storing waste drilling fluid ) 是由 田玉芹 江少波 刘希明 韦雪 韩保锋 张代森 唐功勋 衣哲 朱妍婷 江汇 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种稳定存放废弃钻井液的方法,其包含以下步骤：(a)对废弃钻井液暂存池进行防渗透处理,在暂存池的底面设有防渗衬垫；(b)在废弃钻井中加入季铵盐类杀菌剂；(c)将分体式机械搅拌器设置于暂存池内进行搅拌,其搅拌桨为螺旋搅拌桨。本发明可降低处理成本,能够快速、有效地实现废弃钻井液的稳定存放。(The invention relates to a method for stably storing waste drilling fluid, which comprises the following steps: (a) carrying out anti-seepage treatment on the temporary storage pool of the waste drilling fluid, wherein an anti-seepage gasket is arranged on the bottom surface of the temporary storage pool; (b) adding a quaternary ammonium salt bactericide into the waste well; (c) the split type mechanical stirrer is arranged in the temporary storage tank for stirring, and the stirring paddle is a spiral stirring paddle. The invention can reduce the treatment cost and can quickly and effectively realize the stable storage of the waste drilling fluid.)

1. A method of stably storing a waste drilling fluid, comprising the steps of:

(a) carrying out anti-seepage treatment on the temporary storage pool of the waste drilling fluid, wherein an anti-seepage gasket is arranged on the bottom surface of the temporary storage pool;

(b) adding a quaternary ammonium salt bactericide into the waste well;

(c) the split type mechanical stirrer, such as a paddle stirrer, is arranged in the temporary storage tank for stirring, and the stirring paddle is a spiral stirring paddle.

2. The method of claim 1, wherein the quaternary ammonium salt bactericide is selected from dodecyl dimethyl benzyl ammonium chloride, polyazacycloquaternary ammonium salt (FQ-C), polyquaternary ammonium salt (TS-819), or diquaternary ammonium salt (BQN-2), or a mixture of any two thereof.

3. The method of claim 2, wherein the biocide concentration is 50-500mg/L of the waste drilling fluid.

4. The method as claimed in claim 1 or 2, wherein the helical stirring paddle comprises a hub and blades, wherein the blades are distributed on the hub along a helical direction, the helical blades are helical surface type, the outer diameter is 100-700mm, the inner diameter is 50-250mm, the pitch is 200-900mm, the plate thickness is 2-8mm, and the number of the secondary gears is 3-9.

5. The method according to claim 1, wherein the buffer tank is rectangular, the stirrers are arranged at intervals of 1.0 to 2.5 m in the longitudinal direction, the peripheral speed of the outer edge of the blade is 5 to 25m/s, the stirring time interval is 4 to 10d, and the stirring time is 5 to 15 hours per time.

6. A process according to claim 2, wherein in the fungicide mixture, the mixture preferably contains a diquaternary ammonium salt (BQN-2), such as dodecyldimethylbenzylammonium chloride and diquaternary ammonium salt (BQN-2), polyquaternary ammonium salt (TS-819) and diquaternary ammonium salt (BQN-2); wherein the proportion of the biquaternary ammonium salt (BQN-2) is 45-75 wt%.

7. The method of claim 1, wherein the liner is selected from the group consisting of plastic sheeting, asphalt, concrete, or chemically treated soil-bentonite blend.

Technical Field

The invention relates to a method for stably storing waste drilling fluid.

Background

With the rapid development of the petroleum industry, various types of wells have different requirements on drilling fluid, the types of the drilling fluid are continuously increased, and additives are increased day by day, so that the waste drilling fluid contains a plurality of reusable active components; meanwhile, due to the complex composition, many components cause certain harm to human bodies and environment. Therefore, if proper treatment and resource recycling are not carried out, the ecological environment is influenced, and simultaneously, the resource is greatly wasted.

At present, the treatment methods of the waste drilling fluid mainly comprise three methods: 1. temporarily stored in a storage station to meet the requirement (the general density is more than or equal to 1.3 g/cm)³) The drilling fluid can be recycled, and the drilling fluid can be used as the drilling fluid to be matched with new slurry for recycling; 2. conveying to a treatment plant for treatment, carrying out solid-liquid separation, conveying supernatant to a sewage treatment station for treatment, pressing part of solid particles into mud cakes, and carrying out harmless treatment uniformly after storage; 3. directly discharging to a ground pool with an impermeable layer, and curing.

It is obvious that the third method, although simple, causes pollution to the ecological environment and also causes great waste of resources. In the second method, the processing cost is high. The first method can realize resource recycling of most of the waste drilling fluid through reasonable preservation and treatment. Except that the density is more than or equal to 1.3g/cm³Besides the drilling fluid is circularly used for well drilling, a resource plugging adjusting technology is also developed for the drilling fluid with lower density. However, in the current method for stably storing the waste drilling fluid, the waste drilling fluid is only stirred regularly, but the waste drilling fluid is easy to deteriorate and waste in summer due to high temperature, easy propagation of bacteria and the like, and the environment is polluted due to large smell. Therefore, the stable storage was investigatedThe method for discharging the waste drilling fluid has very important significance for resource utilization of the waste drilling fluid.

Disclosure of Invention

The invention provides a method for stably storing waste drilling fluid, which comprises the following steps:

(a) carrying out anti-seepage treatment on the temporary storage pool of the waste drilling fluid, wherein an anti-seepage gasket is arranged on the bottom surface of the temporary storage pool;

(b) adding a quaternary ammonium salt bactericide into the waste well;

(c) the split type mechanical stirrer, such as a paddle stirrer, is arranged in the temporary storage tank for stirring, and the stirring paddle is a spiral stirring paddle.

The invention provides a method for combining treatment and recycling of waste drilling fluid, reducing treatment cost, being rapid and effective and realizing stable storage of the waste drilling fluid, by taking a waste drilling fluid resource recycling technology as an application background and combining stirrer design, stirring parameter design and bactericide application, aiming at the composition and characteristics of the waste drilling fluid. By using the method, after 6 months, the water separation rate of the waste drilling fluid is less than 5%, and the bacteria content is less than 1000/ml.

Detailed Description

The invention provides a method for stably storing waste drilling fluid, which comprises the following steps:

(a) carrying out anti-seepage treatment on the temporary storage pool of the waste drilling fluid, wherein an anti-seepage gasket is arranged on the bottom surface of the temporary storage pool;

(b) adding a quaternary ammonium salt bactericide into the waste well;

(c) the split type mechanical stirrer, such as a paddle stirrer, is arranged in the temporary storage tank for stirring, and the stirring paddle is a spiral stirring paddle.

In a preferred embodiment, the quaternary ammonium salt bactericide is selected from dodecyl dimethyl benzyl ammonium chloride, polyazacycloquaternary ammonium salt (FQ-C), polyquaternary ammonium salt (TS-819) or diquaternary ammonium salt (BQN-2), or a mixture of any two thereof.

In a preferred embodiment, the biocide concentration is 50 to 500mg/L of the waste drilling fluid.

In a preferred embodiment, the spiral stirring paddle comprises a hub and blades, wherein the blades are distributed on the hub along a spiral line direction, the spiral blades are of a spiral surface type, the outer diameter of the spiral blade is 100-700mm, the inner diameter of the spiral blade is 50-250mm, the pitch of the spiral blade is 200-900mm, the plate thickness is 2-8mm, and the number of the secondary gears is 3-9.

In a preferred embodiment, the split mechanical agitator is a paddle agitator; the stirring paddle is a spiral stirring paddle. The rotating speed of the paddle stirrer is 300-500 rad/min.

In a preferred embodiment, the buffer tank is rectangular, the stirrers are arranged at intervals of 1.0 to 2.5 m along the longitudinal direction, the peripheral speed of the outer edge of the blade is 5 to 25m/s, the stirring time interval is 4 to 10d, and the stirring time is 5 to 15 hours per time.

In a preferred embodiment, the germicidal mixture preferably contains a bis-quaternary ammonium salt (BQN-2), such as dodecyl dimethyl benzyl ammonium chloride and bis-quaternary ammonium salt (BQN-2), polyquaternary ammonium salt (TS-819) and bis-quaternary ammonium salt (BQN-2); wherein the proportion of the biquaternary ammonium salt (BQN-2) is 45-75 wt%.

In a preferred embodiment, the liner is selected from the group consisting of plastic sheeting, asphalt, concrete or chemically treated soil-bentonite blends.

In the invention, the structure of the temporary storage pool of the waste drilling fluid is required to be solid and impermeable, and the liner can be selected from plastic soft films, asphalt, concrete or chemically treated soil-bentonite blends and the like. The temporary storage pool can be designed into a rectangular shape according to the geographical environment and the placement position. In order to maintain the stability of the waste drilling fluid, the waste drilling fluid needs to be periodically stirred. According to the basic properties of the waste drilling fluid, a split type mechanical stirrer such as a paddle type stirrer is adopted in the waste drilling fluid temporary storage pool, and meanwhile, a stirring paddle is designed into a spiral stirring paddle, adopts a ship-like propeller structure and consists of a hub and a paddle; the blade section and the hub axis have an inclination angle of 10 degrees; the spiral stirring blades are distributed on the propeller hub along the spiral direction, the flow velocity distribution of the flow field in the axial direction and the flow velocity distribution of the flow field are determined by the track trend of the spiral, the spiral blades are in a spiral surface type, the outer diameter is 100-700mm, the inner diameter is 50-250mm, the screw pitch is 200-900mm, the plate thickness is 2-8mm, the number of the auxiliary gears is 3-9, and the number of the auxiliary gears corresponds to the number of the blades. The rotating speed of the paddle stirrer is 300-500 rad/min.

The structure has the characteristics of simple structure, high thrust, good axial flow characteristic and the like, can accelerate mixing and has higher stirring efficiency.

The stirring condition of the temporary storage pool is crucial because the stable storage of the waste drilling fluid can be effectively realized. In this connection, the stirring power can be divided theoretically into two aspects, namely stirrer power and stirring work power, but in practice only or mainly stirrer power is generally considered. The agitator power, P, can be calculated as follows:

P＝Kd⁵N³ρ

① structure and operation parameters of the stirrer, such as the type of the stirrer, the diameter and width of the blades, the inclination angle of the blades, the number of the blades, the rotating speed of the stirrer, ② physical properties of the stirring medium, such as the density, the viscosity of the medium and the size of solid particles, a flow field of the helical stirrer is simulated by adopting a dynamic reference system model in Fluent software, the rotating speed of fluid around the helical stirring paddle is firstly set, then the stirring paddle and fluid in a pool are determined to synchronously rotate, boundary conditions and property parameters of waste drilling fluid are brought in, the flow field of the helical stirring paddle is simulated by calculation, the helical stirrer is arranged at intervals of 1.0-2.5 meters, the peripheral speed of the blades is 5-25m/s, the stirring time interval is 4-10d, and each stirring time is 5-15h³And the solid particle size D90 is less than or equal to 75 microns.

Because the underground temperature is higher, thickening agents such as xanthan gum, starch and the like are usually added during drilling, and a large amount of bacteria (mainly saprophytic bacteria, sulfate reducing bacteria and iron bacteria) are bred when the drilling fluid returns to the temporary storage tank through high-temperature circulation. Thereby leading the waste drilling fluid to deteriorate and become smelly and causing the deterioration of the working environment; meanwhile, the waste drilling fluid is easy to cause a series of problems of metal corrosion, stratum blockage, chemical agent deterioration and the like during application, and huge economic loss is caused for production and operation of oil fields. Therefore, the types and the contents of bacteria in the waste drilling fluid are generally required to be measured, and bactericides are added in a targeted manner for pretreatment. The saprophytic bacteria content is mainly determined by adopting a plate culture colony counting method, and the sulfate reducing bacteria and the iron bacteria are mainly determined by adopting an oil field injection water bacteria analysis method-absolute dilution method according to the oil and gas industry standard SY/T0532- "2012" of the people's republic of China. The bactericide adopts quaternary ammonium salt bactericides of dodecyl dimethyl benzyl ammonium chloride, polyazetidinium salt (FQ-C), polyquaternium (TS-819) and biquaternary ammonium salt (BQN-2), and can be used singly or compounded when in use. The concentration of the bactericide is 50-500mg/L waste drilling fluid.

In the present invention, unless otherwise specified, the operation is carried out under normal temperature and pressure conditions.

In the present invention, all proportions, parts and percentages are by mass unless otherwise indicated.

In the present invention, the substances used are all known substances, and are commercially available or synthesized by known methods.

In the present invention, the apparatus or equipment used is conventional apparatus or equipment known in the art, and is commercially available.