CN104060955A - Drilling fluid purifying plant and method adopted to purify drilling fluid - Google Patents

Abstract

The invention relates to a drilling fluid purification device and a method for purifying drilling fluid. The drilling fluid purification device includes: a fluid storage tank, a drilling fluid purifier connected to the fluid storage tank, and a circulation pump for circulating the drilling fluid between the fluid storage tank and the drilling fluid purifier. The drilling fluid purifier includes a The liquid pipe, the separator of the upper outlet and the lower outlet and the vibrating screen communicated with the lower outlet of the separator. The circulation pump pumps the drilling fluid from the liquid storage tank to the separator, and the fluid with plugging material discharged from the upper outlet of the separator directly flows into the downstream equipment, while the material discharged from the lower outlet of the separator is separated by a vibrating screen Afterwards, the fluid portion is returned to the reservoir to remove harmful solids. The drilling fluid purifying device can not only purify the drilling fluid, but also ensure that the plugging material in the drilling fluid is within the effective content range without having to replenish the plugging material in large quantities.

Description

Drilling fluid purification device and method for purifying drilling fluid

technical field

The invention relates to a drilling device, in particular to a drilling fluid purification device. The invention also relates to a method for purifying drilling fluid using the drilling fluid purification device.

Background technique

During oil drilling, four-stage solids control equipment including shale shaker, desander, desilter and centrifuge are usually used to filter and purify drilling fluid. However, in the drilling process using this four-stage solid control equipment, the problem of lost circulation is often encountered. Once lost circulation occurs, it will not only delay the drilling time and lose drilling fluid, but also damage oil and gas layers, and may cause complex accidents such as stuck pipe, collapse, and blowout due to the instability of the well wall, which seriously restricts oil exploration. development speed.

At present, in the process of oil drilling, the drilling fluid with plugging while drilling (that is, the drilling fluid with plugging materials while drilling) is usually used for circulating drilling. In order to solve the lost circulation problem, two methods are usually adopted: (1) Turn off the solid control equipment, but the drilling fluid cannot be filtered, resulting in cuttings that cannot be removed in time and easily causing downhole complications such as sand sinking and sticking; (2) Turn on the solid control equipment , but the plugging material while drilling will be screened out when it returns from the wellhead and flows through the vibrating screen, so it is necessary to replenish the plugging material while drilling in time, which greatly increases the drilling cost and drilling fluid maintenance workload. Therefore, there is an urgent need for a method that can not only filter the drilling fluid but also maintain the concentration of the plugging material while drilling in the drilling fluid.

Contents of the invention

In view of the above problems, the present invention proposes a drilling fluid purification device. The drilling fluid purifying device can not only purify the drilling fluid, but also ensure that the plugging material in the drilling fluid is within the effective content range without having to replenish the plugging material in large quantities. In addition, the present invention also relates to a method for purifying drilling fluid using the drilling fluid purification device.

According to a first aspect of the present invention, a drilling fluid purification device is proposed, comprising:

A fluid storage tank, a drilling fluid purifier connected to the fluid storage tank, and a circulating pump for circulating the drilling fluid between the fluid storage tank and the drilling fluid purifier, and the drilling fluid purifier includes a fluid inlet connected to the circulating pump pipe, upper and lower outlet separators and a vibrating screen connected to the lower outlet of the separator, wherein the circulation pump pumps the drilling fluid containing harmful solids from the liquid storage tank to the separator, and from the upper outlet of the separator The discharged fluid with plugging material flows directly into the downstream equipment, and the material discharged from the lower outlet of the separator is separated by a vibrating screen, and the fluid part returns to the liquid storage tank to remove harmful solids.

According to the drilling fluid purification device of the present invention, by using a separator, most of the lost circulation plugging materials do not pass through the vibrating screen, thereby avoiding a large amount of lost circulation plugging materials from being screened out. The combined use of the separator and the vibrating screen can separate harmful solids in the drilling fluid, and realize the filtration and purification of the drilling fluid.

In one embodiment, the separator is a container comprising a tapered portion and a cylindrical portion arranged at the large end of the tapered portion, wherein the cylindrical portion faces upwards, the small end of the tapered portion faces downwards, and the liquid inlet pipe is arranged on the column. On the circumferential side of the cylindrical part, the upper outlet is arranged at the top of the cylindrical part, and the lower outlet is arranged at the bottom of the small end part.

In a specific embodiment, the length of the part of the upper outlet of the separator inside the separator is between 180 mm and 220 mm, and the cone angle of the tapered part is between 15° and 19°. In a preferred embodiment, the length of the part of the upper outlet of the separator inside the separator is 205 mm, and the cone angle of the tapered part is 17°. The conical separator with this design can efficiently separate the plugging materials and harmful solids in the drilling fluid, and realize the filtration and purification of the drilling fluid.

In one embodiment, the drilling fluid purification device further includes a liquid introduction pipeline for directly introducing the drilling fluid to the vibrating screen. With this arrangement, when it is only necessary to purify the drilling fluid, that is, when there is no need to keep the plugging material or the drilling fluid does not contain the plugging material, the drilling fluid can be filtered quickly and the circulation speed of the drilling fluid can be increased. In a preferred embodiment, a valve is arranged on the liquid introduction pipeline. In this way, the flow path of drilling fluid can be controlled conveniently.

In one embodiment, a liquid collecting funnel is further arranged between the lower outlet of the separator and the vibrating screen. This collecting funnel can guide the material flow and prevent the loss of drilling fluid.

In one embodiment, the mesh size of the screen of the vibrating screen is between 0.25 mm and 0.425 mm. The screen with this structure can only allow the lost circulation plugging material in the drilling fluid discharged from the lower outlet of the separator to pass through, while harmful solids such as cuttings cannot pass through, so as to further recover the lost circulation plugging material.

According to a second aspect of the present invention, a method for purifying drilling fluid using the drilling fluid purification device described above is proposed, including:

Step 1: Close the valve on the liquid induction pipeline and introduce the drilling fluid containing harmful solids into the liquid storage tank;

Step 2: Pump the drilling fluid in the liquid storage tank to the separator through the circulation pump;

Step 3: The fluid with plugging material discharged from the upper outlet of the separator is directly introduced into the downstream equipment, and the material discharged from the lower outlet of the separator is separated by a vibrating screen, and the fluid part is returned to the liquid storage tank Hazardous solids are excluded.

In one embodiment, when only the drilling fluid is purified, the valve provided on the liquid diversion pipeline is opened, so that the drilling fluid enters the vibrating screen only through the fluid diversion pipeline.

In this application, the terms "upper" and "lower" are defined with reference to the direction of gravity.

Compared with the prior art, the present invention has the advantage that the leakage blocking material does not pass through the vibrating screen by using the separator, thereby preventing the leakage blocking material from being screened out. The combined use of the separator and the vibrating screen can separate harmful solids in the drilling fluid, and realize the filtration and purification of the drilling fluid. The purifier includes a suction line that directs drilling fluid to the shale shaker. With this arrangement, when it is only necessary to purify the drilling fluid, that is, when there is no need to keep the plugging material or the drilling fluid does not contain the plugging material, the drilling fluid can be filtered quickly and the circulation speed of the drilling fluid can be increased. In addition, the drilling fluid purification device of the present invention is simple in structure and relatively convenient in operation.

Description of drawings

Hereinafter, the present invention will be described in more detail based on the embodiments with reference to the accompanying drawings. in:

Fig. 1 is a schematic structural view of a drilling fluid purification device according to the present invention;

Fig. 2 is a schematic structural view of a purifier used in the drilling fluid purification device of Fig. 1;

Fig. 3 is a schematic structural view of a separator used in the purifier according to the present invention.

In the figures, the same components are designated by the same reference numerals. The drawings are not drawn to scale.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

Fig. 1 schematically shows the structure of a drilling fluid purification device 100 according to the present invention. The drilling fluid purification device 100 includes a storage tank 1 for storing drilling fluid, a purifier 2 communicating with the storage tank 1 , and a circulating pump 11 for circulating the drilling fluid between the storage tank 1 and the purifier 200 . The fluid storage tank 1 can not only store the drilling fluid but also precipitate the denser substances in the drilling fluid, such as rock particles in the drilling fluid, to achieve pre-separation. As shown in FIG. 1 , the fluid storage tank 1 can be directly communicated with external drilling fluid through a pipeline 3 to introduce drilling fluid. In one embodiment, a valve 13 is also provided on the pipeline 3 to prevent the drilling fluid from directly entering the fluid storage tank 1 .

In the embodiment shown in Figure 1, an opening (not shown) is provided on the top of the fluid storage tank 1, and the purifier 200 is directly installed at the opening so that the design of the drilling fluid purification device 100 is more compact, and the size is correspondingly smaller. FIG. 2 schematically shows the structure of the purifier 200 .

As shown in FIG. 2 , the purifier 200 includes a separator 201 for separating the drilling fluid and a vibrating screen 211 capable of filtering harmful solids in the drilling fluid, such as rock debris. A liquid inlet pipe 203 is provided on the side of the separator 201 , an upper outlet 202 is arranged on the upper part of the separator 201 , and a lower outlet (304 in FIG. 3 ) is arranged on the lower part of the separator 201 . In the assembled state, the liquid inlet pipe 203 communicates with the circulation pump 11 through the pipeline 6 (as shown in FIG. 1 ) to pump the drilling fluid in the liquid storage tank 1 to the inside of the separator 201 . The upper outlet 202 of the separator 201 is directly connected to the downstream components (such as the mud tank 8 in FIG. 1 ) through the pipeline 5 (as shown in FIG. 1 ) to further process the material discharged from the upper outlet 202, and the separator 201 The lower outlet is aligned with the vibrating screen 211 to enable discharge of material onto the vibrating screen 211 . In a preferred embodiment, a liquid collection funnel 205 is also provided between the lower outlet of the separator 201 and the vibrating screen 211 . The liquid collection funnel 205 is used to guide the material flow and prevent the loss of drilling fluid. In order to make the vibrating screen 211 work smoothly, the purifier 200 also includes a driving device for driving the vibrating screen 211, such as a motor 215, a buffer spring 206 for protecting the vibrating screen 211, a buffer spring limit rod 208, etc. Those skilled in the art are well known, and will not be repeated here for the sake of simplicity.

Fig. 3 schematically shows the structure of a separator 201 according to the present invention. As shown in FIG. 3 , the separator 201 includes a conical portion 305 with a small end facing downward and a cylindrical portion 306 disposed at a large end of the conical portion 305 . Viewed as a whole, the separator 201 is in the shape of a funnel. The liquid inlet pipe 203 is arranged on the circumferential side of the cylindrical portion 306 , and the upper outlet 202 is also arranged at the top of the cylindrical portion 306 , while the lower outlet 304 is arranged at the bottom of the small end portion of the conical portion 305 . When the drilling fluid carrying cuttings enters the separator 201 from the liquid inlet pipe 203 along the tangential direction of the cylindrical part 306 at a certain speed, the drilling fluid will rotate at a high speed (as shown by the circumferential arrow in FIG. 3 ). During the rotation process, the larger and heavier cuttings in the drilling fluid are thrown towards the wall of the device under the action of centrifugal force, descend along the casing and be discharged through the lower outlet 304; Change the direction to form an internal spiral upward movement (as shown by the arrow facing the upstream direction in FIG. 3 ), and finally leave the separator 201 through the upper outlet 202 . In this way, the purpose of separating rock cuttings with a density greater than water in the drilling fluid is achieved.

In order to ensure that the separator 201 can recover the lost circulation plugging materials, such as walnut shells and sawdust, etc., which are denser than water in the drilling fluid while separating cuttings with a density higher than water in the drilling fluid, in one embodiment, the separation The device 201 is configured such that the cone angle of the conical portion 305 is between 15°-19°, and the length of the part of the upper outlet 202 inside the separator 201 is between 180mm-220mm. Preferably, the length ratio of the cylindrical portion 306 of the separator 201 to the tapered portion 305 is between 1:3 and 1:2, the inner diameter of the cylindrical portion 306 of the separator 201 is between 250 mm and 300 mm, and the liquid inlet pipe 203 The inner diameter of the upper outlet 202 is between 65mm and 80mm, the inner diameter of the upper outlet 202 is between 110mm and 130mm, and the inner diameter of the lower outlet 304 is between 35mm and 55mm, so the processing capacity of the separator 201 is between ^25m3 /hr and ^60m3 /hr . The separator 201 with this structure can separate the cuttings, and at the same time, the plugging material with a density lower than water can leave the separator 201 from the upper outlet 202 along with the drilling fluid. Therefore, the content of the plugging material in the drilling fluid can be ensured while the cuttings are separated. In a specific embodiment, the length of the part of the upper outlet 202 of the separator 201 inside the separator 201 is 205mm, and the cone angle of the tapered portion 305 is 17°. Preferably, the inner diameter of the cylindrical part 306 of the separator 201 is 300mm, the inner diameter of the liquid inlet pipe 203 is 78mm, the inner diameter of the upper outlet 202 is 120mm, and the inner diameter of the lower outlet is 55mm, the cylindrical part 306 of the separator 201 and the tapered part The length ratio of 305 is 0.45, and the processing capacity of the separator 201 with this structure is 55m ³ /hr.

As shown in FIG. 2 , the vibrating screen 211 screens out harmful solids in the material discharged from the lower outlet 304 of the separator 201 , and the remaining drilling fluid is directly leaked into the liquid storage tank 1 . In this way, the cooperative use of the separator 201 and the vibrating screen 211 not only realizes filtering and purifying the drilling fluid, but also retains the plugging material in the drilling fluid. In a preferred embodiment, the mesh size of the screen of the vibrating screen 211 is 0.25mm. This kind of screen prevents cuttings from passing through, but the plugging materials with similar density and small particle size remaining in the drilling fluid, such as calcium carbonate particles with a particle size of less than 0.25mm, can pass through, so that the plugging materials can be further recovered .

As shown in FIG. 1 , the drilling fluid purification device 100 also includes a liquid introduction pipeline 4 that directly introduces the drilling fluid to the vibrating screen 211 . Like this, when there is no plugging material in the drilling fluid or when the content of the plugging material in the drilling fluid does not need to be ensured, the drilling fluid can be directly discharged to the vibrating screen 211 through the liquid introduction pipeline 4 for filtering, so as to reduce the leakage of the drilling fluid. The flow path increases the circulation speed of the drilling fluid. In a preferred embodiment, a valve 10 is provided on the liquid introduction pipeline 4 . When it is only necessary to filter the drilling fluid, the valve 10 is opened, the valve 13 is closed, and the circulating pump 11 is stopped (that is, the separator 201 is not used). When not only the drilling fluid needs to be filtered but also the lost circulation material needs to be kept, the valve 10 is closed, the valve 13 is opened, and the circulating pump 11 is started (that is, the separator 201 is used). Therefore, the switching of the drilling fluid purification device 100 between different use modes is facilitated by setting the valve 10 .

Next, a method for purifying drilling fluid using the drilling fluid purification device 100 according to the present invention will be described according to FIGS. 1 and 2 .

Firstly, the valve 10 on the liquid introduction pipeline 4 is closed, and the valve 13 is opened to introduce drilling fluid into the liquid storage tank 1 through the pipeline 3 . Next, the circulation pump 11 is started to pump the drilling fluid in the liquid storage tank 1 to the separator 201 . Finally, through the pipeline 6, the drilling fluid with plugging material discharged from the upper outlet 202 of the separator 201 is directly introduced into the mud tank 8 for the next step of processing, and the material discharged from the lower outlet of the separator 201 is passed through a vibrating screen After 211 separation, harmful solids are removed, and the remaining drilling fluid is returned to the liquid storage tank 1.

When it is only necessary to purify the drilling fluid, the valve 10 arranged on the liquid introduction pipeline 4 is opened, and the valve 13 on the pipeline 3 is closed, so that the drilling fluid enters the vibrating screen 211 only through the liquid introduction pipeline 4 . After removal of harmful solids, the remaining drilling fluid enters the liquid storage tank 1 .

Finally, it should be noted that: the above description is only a preferred embodiment of the present invention, and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a drilling-liquid purifying apparatus, comprising:

Fluid reservoir, the drilling fluid cleaner being connected with described fluid reservoir, and the circulation pump that drilling fluid is circulated between fluid reservoir and drilling fluid cleaner,

Described drilling fluid cleaner comprises with the eliminator of the feed tube, upper outlet and the lower outlet that are communicated with described circulation pump and the vibrosieve being connected with the lower outlet of described eliminator,

Wherein, described circulation pump is pumped into eliminator by the drilling fluid that comprises harmful solid from described fluid reservoir, the fluid with loss circulation material of discharging from the upper outlet of described eliminator flows directly into upstream device, and from described eliminator outlet discharge material through described vibrosieve from after, fluid section turn back to described fluid reservoir and will be harmful to solid remove.

2. drilling-liquid purifying apparatus according to claim 1, it is characterized in that, described eliminator is the container that comprises tapering part and be arranged on the cylindrical section of the large end of tapering part, wherein, upward, downward, described feed tube is arranged in the circumferential sides of described cylindrical section the small end of tapering part cylindrical section, described upper outlet is arranged on the top of described cylindrical section, and described lower outlet is arranged on the bottom of described small end part.

3. drilling-liquid purifying apparatus according to claim 2, is characterized in that, the upper outlet of described eliminator is in the length of the part of described eliminator inside between 180mm-220mm, and the cone angle of tapering part is between 15 °～19 °.

4. drilling-liquid purifying apparatus according to claim 3, is characterized in that, the upper outlet of described eliminator is 205mm in the length of the part of described eliminator inside, and the cone angle of tapering part is 17 °.

5. according to the drilling-liquid purifying apparatus described in any one in the claims, it is characterized in that, also comprise the liquid guiding tube road that drilling fluid is introduced directly into described vibrosieve.

6. according to the drilling-liquid purifying apparatus described in any one in the claims, it is characterized in that, between the lower outlet of described eliminator and described vibrosieve, be also provided with liquid collecting funnel.

7. according to the drilling-liquid purifying apparatus described in any one in the claims, it is characterized in that, the mesh size of the screen cloth of described vibrosieve is between 0.25mm～0.425mm.

8. drilling-liquid purifying apparatus according to claim 5, is characterized in that, on described liquid guiding tube road, is provided with valve.

9. use, according to the drilling-liquid purifying apparatus clean drilling liquid method described in any one in the claims, comprising:

Step 1: close the valve on described liquid guiding tube road and the drilling fluid that comprises harmful solid is incorporated in described fluid reservoir;

Step 2: the drilling fluid pump in described fluid reservoir is delivered in eliminator by circulation pump;

Step 3: the fluid with loss circulation material of discharging from the upper outlet of described eliminator is directly introduced upstream device, and by from described eliminator outlet discharge material through described vibrosieve from after, fluid section turn back to described fluid reservoir and will be harmful to solid get rid of.

10. method according to claim 9, is characterized in that, in the time of clean drilling liquid only, opens the valve being arranged on described liquid guiding tube road, makes drilling fluid only enter described vibrosieve by liquid guiding tube road.