CN106830586A - A kind of drilling mud cavitation method handling process - Google Patents

Abstract

The invention discloses a drilling mud cavitation treatment process, which includes five parts: stirring, screening, cavitation, swirling oil skimming and three-phase separation. After the drilling mud is stirred with water, it is screened to remove large solid impurities, and water is added. After stirring evenly, cavitation treatment is carried out, and then through cyclone skimming, most of the oil is recovered and discharged to the oil storage tank. After cyclone oil skimming, the remaining mixture is added with demulsifier and then enters the three-phase separator. The separated top floating oil is discharged into the oil storage tank, the separated sewage is subjected to cyclone degreasing, and the separated aqueous sludge is subjected to solid-liquid separation. separate. The low water content oil obtained by cyclone degreasing enters the oil storage tank, and is transported outside after settling, and the obtained low oil content water enters the water storage tank for recycling. The drilling sludge obtained from solid-liquid separation can be discharged outside, and the obtained low-solid water enters the water storage tank for recycling. After the oil-based mud is treated, the oil yield is higher than 95%, the oil content of the drilling sludge is lower than 1%, and the water is recycled. The drilling sludge obtained by this process can be directly discharged on site without secondary pollution.

Description

A drilling mud cavitation treatment process

technical field

The invention relates to a waste drilling mud treatment process, in particular to a drilling mud cavitation treatment process.

Background technique

In recent years, with the wide application of oil-based mud in various drilling platforms, how to effectively deal with oily drilling mud has attracted more and more attention from scientific researchers and oilfield technicians.

In 2016, Shi Jianying's invention patent 201610641515.9-"Mud Treatment System", disclosed a method of mud treatment at the wellhead that mainly adopts screening, which mainly solves the problem that the mud treatment system in the prior art cannot effectively improve the mud flowing into the screening device Mobility issues.

In 2016, Ni Hongxia, Fu Jianguo, Liu Jingli, etc. patented the invention patent 201610276855.6-"Recycling and Treatment Method of Oil-based Mud", which was processed by heating and condensation, and finally obtained furnace ash for on-site discharge.

In 2015, the utility model patent 201520121490.0-"Waste Oil-based Mud Treatment Device While Drilling" by Li Guanghuan, Huang Daquan, Wu Wenru, etc., discloses the recovery of base oil by dosing and physical separation. The recovery rate reaches 85%, and the waste solid phase Oil content is less than 0.1%.

There are many other similar invention patents, such as the invention patent 201620399516.2 of Qiao Jin'an, Jiang Zhongnan, Li Qiang, etc. - "Oil-based mud vehicle-mounted temperature-controlled pyrolysis fractionation harmless treatment device"; Liu Ling's 201610039761.7-"An oil-based mud Drilling cuttings treatment method", invention patent 201620190883.1-"A Simplified Oilfield Waste Oil Slurry Treatment Device" by Yang Lifang, Gao Ansheng, Liu Xiaohui, etc.

Based on the above analysis, it is found that many invention patents and scientific research personnel either use heat treatment for drilling mud treatment, which requires high temperature and high pressure, and consumes a lot of energy; or use the method of direct dosing and separation, which has low efficiency, large consumption of chemical reagents, and high recovery costs. . Therefore, low-cost, high-efficiency, safe, reliable, and simple-to-operate processes need to be discovered urgently.

Contents of the invention

The technical problem to be solved by the present invention is: in order to solve the problems of high cost and low efficiency of the existing drilling mud treatment, the present invention provides a drilling mud cavitation treatment process.

The technical solution adopted by the present invention to solve the technical problem is: a drilling mud cavitation treatment process, including five processes of stirring, screening, cavitation, cyclone skimming and three-phase separation, wherein the three-phase separation step is divided into For oil-water separation and solid-liquid separation, specifically include the following steps:

After the drilling mud is mixed with water, it is screened to remove large solid impurities;

Then add water and stir evenly, then carry out cavitation treatment, so that oil and water, oil sludge or oil sand are released from each other;

After swirl skimming, most of the oil is recovered and discharged to the oil storage tank;

After cyclone skimming, the remaining oil, mud and water mixture is added to the demulsifier and then enters the three-phase separator, and the separated top floating oil is discharged into the oil storage tank, and the separated sewage is subjected to cyclone degreasing, and the separated Drilling sludge is separated from solid and liquid; the low water content oil obtained by cyclone degreasing enters the oil storage tank, and is transported outside after settling, and the obtained low oil content water enters the water storage tank.

The drilling sludge obtained from solid-liquid separation can be discharged outside, and the obtained low-solid water enters the water storage tank for recycling. After the oil-based mud is treated by this process, the yield of oil is higher than 95%, the oil content of the drilling sludge is lower than 1%, and the water is recycled. The process adopts purely mechanical and physical methods to save energy, and the processed drilling sludge can be directly discharged on site without secondary pollution.

During the sieving process, but not limited to secondary or above vibrating sieves with a mesh number of 40 to 80 are used to remove large particles of impurities.

In the cavitation process, a hydraulic cavitator is used for cavitation. The upper part of the hydraulic cavitator is a homogeneous chamber, and the lower part is a cavitation chamber. The hydraulic cavitator has three inlets, namely the liquid inlet, the circulating water inlet and the Cavitation fluid flow inlet. The material fed into the liquid inlet is sieved drilling mud mixture with a specified particle size range and concentration, and the incoming liquid from the circulating water inlet is the bottom water in the end water storage tank of the process flow (drilling mud cavitation treatment process of the present invention) , further mixed with the liquid inlet material to improve the separation effect in the cavitation cavity.

The mixed liquid sieved by the upper stage is used as the incoming liquid of the cavitation liquid inlet and the incoming liquid of the circulating water inlet. Both are pressurized by the booster pump to reach the cavitation pressure required by the system and injected into the cavitation chamber, and the homogeneous mixed liquid is Cavitation, when cavitation occurs, the oil that wraps the solid is stripped from the solid surface, the state of water-in-oil and oil-in-water is broken, and the mixed liquid of oil, water and solid is basically in a free state. The effect of cavitation directly affects the separation efficiency of the entire process. The cavitation process of the present invention is a non-circulation process, and the mixed liquid enters the next stage of swirling oil skimming process after cavitation once.

In the process of swirling oil skimming, several cyclones are installed in parallel and vertically in a vertical container, and the vertical container is divided into three chambers, the upper and lower are oil collecting chamber, feeding chamber and water collecting chamber; The cyclone has an overflow port, a feed port and a bottom flow port, which are respectively located in the oil collection chamber, feed chamber and water collection chamber of the container, and the oil collection chamber and the outlet of the water collection chamber are equipped with regulating valves. The cyclone is an oil removal cyclone. The low water content oil obtained in the cyclone skimming process enters the oil storage tank, and the obtained underflow mixed liquid mainly containing solids, water and a small amount of oil enters the next stage of three-phase separation treatment.

The water storage tank is used to collect low oily water separated by other equipment and provide circulating water for other equipment. In order to meet the needs of hydraulic cavitation treatment, the water storage tank is equipped with a heater to control the water temperature at 40°C to 60°C. ℃.

The water in the water storage tank is pressurized by a high-pressure pump and supplied to various water-demanding equipment, and the pressure is controlled at 0.4-0.6 MPa. Due to the large solid content of the drilling mud, the materials in the entire process must be in a flowing state, and the drilling sludge after three-phase separation takes away part of the liquid, so the water in the water storage tank needs to be continuously replenished.

In the three-phase separation process, a three-phase separator is used. The three-phase separator is composed of a gravity sedimentation separator, a cyclone degreaser and a horizontal screw discharge centrifuge. The oil is collected by the device, and the bottom flow sludge water of the gravity sedimentation separator is dehydrated by a horizontal screw discharge centrifuge. The floating oil at the top of the gravity settling separator enters the oil storage tank; the overflowed oily water is low oily water, after being degreased by the cyclone degreaser, the overflow enters the oil storage tank, and the bottom water enters the water storage tank for preparation Circulating water is used; the bottom flow of the gravity sedimentation separator containing drilling sludge is dehydrated by a horizontal screw discharge centrifuge, the sewage enters the water storage tank, and the obtained high-concentration drilling sludge can be discharged for post-treatment. The three-phase separation process is not limited to the above-mentioned process method, and a three-phase horizontal screw discharge centrifuge can also be used for separation.

The lower part of the oil storage tank has an automatic water cutter, which automatically opens and closes the bottom valve according to the height of the oil-water layer interface to release the water in the lower layer.

The beneficial effect of the present invention is that the high-concentration drilling sludge obtained in the present invention can be directly discharged on-site after subsequent drying and other treatments; the three-phase oil, water and solid are peeled off each other by using the cavitation method. , avoiding the use of other chemical reagents, reducing the burden of subsequent treatment; the water in the present invention is recycled, which reduces the waste of energy; the process flow is short, continuous operation, no need for workers to perform other operations, the pressure of the entire system is low, and it is safe Reliable, low temperature, and less energy consumption than other processing methods such as ultrasonic and pyrolysis.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a process flow diagram of the present invention.

Figure 2 is a process flow diagram of an embodiment of the present invention.

detailed description

Now in conjunction with the technological process of accompanying drawing, the present invention is described in detail.

A drilling mud cavitation treatment process of the present invention is especially suitable for oil-based drilling mud treatment, including stirring, screening, cavitation, cyclone skimming and three-phase separation, wherein the three-phase separation is divided into oil-water separation and Solid-liquid separation. After the drilling mud is mixed with water, it is screened to remove large solid impurities, then mixed with water and then cavitated to release oil, water, oil sludge or oil sand, and then through cyclone skimming, most of the oil is recovered and drained to the storage tank. After cyclone skimming, the remaining oil, mud and water mixture is added to the demulsifier and then enters the three-phase separator. The separated top floating oil is discharged into the oil storage tank, and the separated sewage is subjected to cyclone degreasing, and the separated water contains Sludge undergoes solid-liquid separation. The low water content oil obtained by cyclone degreasing enters the oil storage tank, and is transported outside after settling, and the obtained low oil content water enters the water storage tank for recycling. The drilling sludge obtained from solid-liquid separation can be discharged outside, and the obtained low-solid water enters the water storage tank for recycling. After the oil-based mud is treated by this process, the yield of oil is higher than 95%, the oil content of the drilling sludge is lower than 1%, and the water is recycled. The process adopts purely mechanical and physical methods to save energy, and the processed drilling sludge can be directly discharged on site without secondary pollution.

The oil-based mud in the following table is taken as an example to describe the treatment process plan.

(1) Take 500kg of drilling mud. Due to the sedimentation of the mud after standing still, water can be added and stirred evenly according to the proportion of each component in the mud to improve its fluidity. The proportion of water in the above-mentioned mud reaches 45.97%, so in this example, circulating water may not be added for stirring, and the material enters sieving after continuous stirring.

(2) After secondary screening, the mesh numbers are 40 mesh and 60 mesh respectively to remove large particles.

(3) After screening, the material enters the cavitation equipment for cavitation. Firstly, 78.1kg of water is added to the water storage tank to make the water concentration reach 54.02%, and the added water is heated to ensure that the temperature of the mixed liquid is between 40 and 50°C. In the cavitation equipment, first mix the material and supplementary water evenly, pressurize the cavitation water to 0.4-0.5MPa by the high-pressure pump, and cavitate the homogenized mixed solution. At this time, the oil, water and solid in the mixed solution are in mutual Unpacked state.

(4) After cavitation, the mixed liquid is first subjected to swirling oil skimming, the overflow fraction is 10%, and the separated overflow oil concentration is 40%, and enters the oil storage tank; the separated underflow enters the three-phase separation of gravity sedimentation.

(5) The fraction of floating oil extracted from the top after gravity settling is 4%, and the oil concentration is 30%, and enters the oil storage tank; the ratio of oil and sewage in the middle is 38.98%, and enters the cyclone for degreasing; the mixture with high solid content at the bottom enters Decanter centrifuge.

(6) The treatment capacity of cyclone degreasing is about 200kg, multi-stage combination, the overflow fraction is controlled at 8%, the concentration reaches 40%, the oil entering the cyclone degreasing is removed, and the bottom flow enters the water storage tank.

(7) The high-solid mixture of three-phase separation enters the decanter centrifuge for solid concentration, and the solid can be subjected to subsequent drying treatment and discharged on the spot. After analysis, the solid contains 0.14% oil, and other oils follow the overflow into the storage tank.

(8) The oil content in the oil storage tank is about 35%, and the settled bottom water enters the water storage tank and circulates in the system.

(9) The oil yield of the system in this example is 98.78%, and the oil content of the drilling sludge is 0.14%.

(10) In this example, the mixing pressure is about 0.4-0.5MPa, and the temperature is 40-50°C. The system is easy to operate, safe and reliable.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (8)

1. a kind of drilling mud cavitation method handling process, it is characterised in that：Including stirring, screening, cavitation, eddy flow oil skimming and three-phase Five processes are separated, wherein three phase separation step is divided into water-oil separating and separation of solid and liquid, specifically includes following steps：

Drilling mud adds water after stirring, by screening, removes big solid impurity；

Then adding water carries out cavitation process after stirring, profit, greasy filth or oil-sand is mutually discharged；

Again by eddy flow oil skimming, most of oil is recovered, and is discharged to oil storage tank；

Enter three phase separator, the top oil slick that will be separated after adding demulsifier through the remaining oil of eddy flow oil skimming, mud, aqueous mixtures Oil storage tank is entered, the sewage for separating carries out cyclone deoiling, the drilling sludge for separating carries out separation of solid and liquid；Cyclone deoiling gained is low to be contained Water oil enters oil storage tank, and outer defeated after sedimentation, the low oil-containing water of gained enters water tank.

2. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：In screening process, use Two grades or more than two grades vibratory sieves, mesh number are 40~80, remove large granular impurity.

3. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：In cavitation processes, use Hydrodynamic cavitation device carries out cavitation, and the top of Hydrodynamic cavitation device is homogeneous chamber, and bottom is cavitation chamber, and Hydrodynamic cavitation utensil has three Entrance, respectively inlet, circulation water inlet and cavitation liquid flow inlet；

It is drilling mud mixed liquor of the screening with regulation particle size range and concentration that inlet enters material, and circulation water inlet carrys out liquid It is the bottom water in the water tank of technological process end, further mixes homogeneous with inlet material improving and separated in cavitation chamber effect Really；

Mixed liquor after upper level screening carrys out liquid as cavitation liquid flow inlet and circulation water inlet carrys out liquid and reached through booster pump supercharging There is the pressure injection cavitation chamber of cavitation needed for system, cavitation is carried out to homogeneous mixed liquor, cavitation will wrap up solid when occurring Oil peeled off from the surface of solids, Water-In-Oil and oil-in-water state are broken, obtain oil, water, solid three-phase be substantially at it is free The mixed liquor of state.

4. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：During eddy flow oil skimming, It is arranged in a vertical vessel using several cyclone parallel Verticals, and vertical vessel is divided into three chambers, up and down It is followed successively by collection chamber, feed cavity and collect cavity；Cyclone has overfall, charging aperture and underflow opening, and respectively positioned at container In collection chamber, feed cavity and collect cavity, collection chamber and collect cavity outlet are provided with control valve.

5. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：Have in the water tank Heater, by water temperature control at 40 DEG C~60 DEG C.

6. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：Water in the water tank Supplied after being pressurized through high-pressure pump it is each need wetting system to use, water of the Stress control in 0.4~0.6MPa, and water tank needs continuous Supplement.

7. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：During three phase separation, Using three phase separator, three phase separator is made up of gravity separator, degreaser cyclone and Horizontal spiral discharging centrifuge, The oily water that gravity separator overflows receives oil through degreaser cyclone, and gravity separator underflow sludge water is through horizontal spiral Conveyer centrifugal is dehydrated.

8. a kind of drilling mud cavitation method handling process as claimed in claim 1, it is characterised in that：The bottom of the oil storage tank There is automatic water cut-off device, the height automatically according to profit layering interfaces opens and closes bottom valve, to release the water of lower floor.