Drilling circulating slurry glue and preparation process thereof

Abstract

The application discloses a kind of drilling circulating slurry glue liquid and preparation process thereof, belong to oil and gas field drilling environmental protection technical field.The preparation process of the drilling circulating slurry glue liquid of the application includes the following steps: homogenization treatment is carried out to waste mud;Add breaker to the waste mud after homogenization treatment and carry out reaction, and after reaction is completed, separation is carried out to obtain filter liquor;The filter liquor is tempered and treated, and the drilling circulating slurry glue liquid is obtained.The drilling circulating slurry glue liquid of the application uses waste mud as raw material, realizes the recycling of waste mud broken glue filter water, and the glue liquid prepared by waste mud broken glue filter water is compared with clean water, and the difference between the rheological properties API loss of the two prepared drilling base slurry and other system stability indexes is within 5%.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology for oil and gas field drilling, specifically to a drilling circulating slurry and its preparation process. Background Technology

[0002] During drilling operations, the amount of waste mud generated is relatively large, with each well producing approximately hundreds to thousands of cubic meters. This is one of the major sources of pollution in the oil and gas industry, and if not treated scientifically and effectively, it will inevitably pose a risk to the local environment. Currently, waste mud treatment methods include chemical debonding-solid-liquid separation, component recovery and recycling, chemical solidification, and biological treatment. Among these, chemical debonding-solid-liquid separation is widely used in drilling sites due to its simplicity and the need for basic equipment.

[0003] The principle of chemical deflocculation-solid-liquid separation involves adding various inorganic and organic chemical flocculants to waste sludge to neutralize the surface charge of solid particles, disrupt their surface structure, and reduce the electrostatic attraction between solid particles. This causes the solid particles to flocculate, agglomerate, and settle, followed by solid-liquid separation using a plate and frame filter press. The separated filtrate, due to its high mineralization, contains large amounts of calcium, magnesium, aluminum, iron, and other metal ions, as well as chloride and sulfate ions, which weaken the hydration and dispersion of clay, making it unusable for slurry preparation. It must be treated by a third-party company to meet discharge standards.

[0004] Due to the enormous water demand at drilling sites, outsourcing the treatment of filtrate inevitably leads to a waste of water resources. Therefore, removing negatively affected ions from water-based drilling mud filtrate, reducing its mineralization, and converting it into a viscous liquid for reuse in drilling circulating mud preparation can not only reduce drilling costs and environmental risks but also alleviate the current water shortage at well sites. This represents a circular, green, and clean technological approach. Summary of the Invention

[0005] The purpose of this invention is to provide a drilling circulating slurry and its preparation process, which solves the technical problems of high salinity of water-based mud filtrate and poor performance of water-based mud filtrate in remixing drilling slurry in the prior art.

[0006] To achieve the above objectives, one embodiment of the present invention provides a process for preparing drilling circulating slurry, comprising the following steps:

[0007] The waste mud was homogenized.

[0008] A desiccant was added to the homogenized waste sludge to react, and the filtrate was obtained after the reaction was completed.

[0009] The filter fluid is conditioned to obtain drilling circulating slurry.

[0010] One preferred embodiment of the present invention involves conditioning the filtrate to obtain a drilling circulation slurry, comprising: adding an ion removal agent to the filtrate for reaction, centrifuging the reacted filtrate, and adding a conditioning agent to the centrifuged filtrate for reaction to obtain the drilling circulation slurry.

[0011] In one preferred embodiment of the present invention, the separated filtrate is recycled back into the homogenization process, and the volume ratio of the recycled filtrate to the waste mud is 1:5-10.

[0012] In one preferred embodiment of the present invention, the waste sludge is stirred during the homogenization process at a stirring rate of 90 rpm to 120 rpm.

[0013] In one preferred embodiment of the present invention, the degumming agent is at least one of aluminum sulfate, polyaluminum chloride, calcium chloride and calcium oxide, and the amount of degumming agent added is 2%-4% of the mass of the waste sludge after homogenization treatment.

[0014] In one preferred embodiment of the present invention, the degreasing agent is added while stirring, and the stirring rate is 90 rpm-120 rpm.

[0015] In one preferred embodiment of the present invention, the ion removal agent is at least one of sodium carbonate, sodium hypotriacetate, and sodium diethylenetriaminepentaacetate, and the amount of ion removal agent added is 0.5%-2% of the mass of the filtrate.

[0016] In one preferred embodiment of the present invention, the conditioning agent is at least one of potassium polyacrylamide, vinyl monomer multi-element copolymer and carboxymethyl cellulose, and the amount of conditioning agent added is 0.5%-1% of the mass of the filtrate after centrifugation.

[0017] In one preferred embodiment of the present invention, the addition rate of the conditioning agent is 1 kg / min to 1.25 kg / min.

[0018] In one preferred embodiment of the present invention, the drilling circulating slurry is reintroduced into the conditioning treatment, and the volume ratio of the reintroduced drilling circulating slurry to the filter fluid is 1:100-200.

[0019] The present invention also discloses a drilling circulation slurry, which is prepared by the above-described preparation process.

[0020] In summary, the beneficial effects of the present invention are as follows:

[0021] 1. The drilling circulating slurry of the present invention uses waste mud as raw material, realizing the recycling of waste mud debonding and filtration water. Furthermore, the slurry prepared with waste mud debonding and filtration water, compared with clean water, shows that the differences in system stability indicators such as rheological properties (AV, PV, YP) ​​and API water loss of the drilling base slurry prepared by the two are within 5%.

[0022] 2. The de-colloiding agent, ion removal agent and conditioning agent used in the drilling circulating slurry preparation process of this invention are all safe and non-toxic, and will not cause secondary pollution to the environment.

[0023] 3. The preparation process of the drilling circulating slurry of the present invention is simple, which greatly saves water resources and drilling costs, and reduces the amount of drilling waste generated.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention will be apparent from the effects described in the description and the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a diagram of the preparation system used in the preparation process of the drilling circulating slurry in this invention;

[0026] Figure 2 This is a flowchart of the preparation process of the drilling circulating slurry in this invention.

[0027] Among them, 1-homogenizing tank, 2-colloid breaking tank, 3-plate and frame filter press, 4-first conditioning tank, 5-centrifuge, 6-second conditioning tank, 7-slurry circulation tank. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0030] The preparation system used in the preparation process of the drilling circulating slurry of this invention is as follows: Figure 1As shown, the system includes a homogenizing tank 1 connected to the well crew's solids control system, a breaker tank 2 connected to the homogenizing tank 1, a plate and frame filter press 3 connected to the breaker tank 2, a first conditioning tank 4 connected to the plate and frame filter press 3, a centrifuge 5 connected to the first conditioning tank 4, a second conditioning tank 6 connected to the centrifuge 5, and a mud circulation tank 7 connected to the second conditioning tank 6.

[0031] This invention provides a process for preparing drilling circulating slurry, such as... Figure 2 As shown, it includes the following steps:

[0032] Step (1): Homogenize the waste mud; specifically, the homogenization tank 1 is connected to the drilling team's solids control system. The homogenization tank 1 collects the waste mud generated by the drilling team's solids control system. The homogenization tank 1 is equipped with at least two agitators that continuously agitate the waste mud inside the homogenization tank 1. The agitator speed is 90rpm-120rpm, so that the drill cuttings particles in the waste mud are crushed during the agitation process, thereby improving the homogenization effect.

[0033] Step (2): Add a desiccant to the homogenized waste sludge and react. After the reaction is completed, separate the filtrate. Specifically, pump the homogenized waste sludge from step (1) into the desiccant tank 2, add the desiccant while stirring, stir and react for 10-20 minutes to desiccate and destabilize the waste sludge, and pump the desiccant and destabilized waste sludge into the plate and frame filter press 3 for solid-liquid separation to obtain the filtrate.

[0034] The process involves stirring with a stirrer at a speed of 90-120 rpm. The desiccant is at least one of aluminum sulfate, polyaluminum chloride, calcium chloride, and calcium oxide. The amount of desiccant added is 2%-4% of the mass of the homogenized waste sludge.

[0035] A portion of the filtrate is recycled back into homogenizing tank 1 in step (1) to reduce the viscosity of the waste mud in homogenizing tank 1 and reduce the workload of the process equipment. The volume ratio of recycled filtrate to waste mud is 1:5-10. The remaining filtrate enters the following step (3).

[0036] Step (3): Condition the filtrate to obtain drilling circulation slurry; specifically, pump the remaining filtrate after remixing into the first conditioning tank 4, add the ion removal agent through a stirrer while stirring, stir and react for 30-40 minutes, then continue to pump it into the centrifuge 5 to remove the precipitate; pump the filtrate after removing the precipitate into the second conditioning tank 6, slowly add the conditioning agent through a stirrer while stirring, stir and react for 2-3 hours to obtain the drilling circulation slurry, and transport the obtained drilling circulation slurry to the mud circulation tank 7 for reuse;

[0037] The agitators in the first conditioning tank 4 and the second conditioning tank 6 rotate at 60 rpm-90 rpm. The ion removal agent is at least one of sodium carbonate, sodium hypotriacetate, and sodium diethylenetriaminepentaacetate, and the amount of ion removal agent added is 0.5%-2% of the mass of the filtrate. The conditioning agent is at least one of potassium polyacrylamide, vinyl monomer multi-component copolymer, and carboxymethyl cellulose, wherein the vinyl monomer multi-component copolymer mainly refers to two models, PAC-141 and PAC-142. The amount of conditioning agent added is 0.5%-1% of the mass of the filtrate after centrifugation to remove the precipitate. Since the conditioning agent is a polymer, its dosing rate needs to be controlled at 1 kg / min-1.25 kg / min to avoid the problem of conditioning agent clumping. The dosing device is a screw quantitative conveying dry powder dosing machine.

[0038] A portion of the prepared drilling circulating slurry is recycled back into the first conditioning tank 4 in a certain proportion. Since the precipitate particles generated during the ion removal process are small, the recycled drilling circulating slurry can cause the precipitate particles suspended in the filter press to aggregate into large flocs, thereby improving the efficiency of solid-liquid centrifugal separation. Preferably, the volume ratio of the recycled drilling circulating slurry to the filter press is 1:100-200.

[0039] The drilling circulating slurry preparation process of this invention enables the recycling of waste mud debonding and filtration water, which greatly saves water resources and drilling costs, and reduces the amount of drilling waste generated.

[0040] The present invention also discloses a drilling circulation slurry, which is prepared by the above-mentioned drilling circulation slurry preparation process.

[0041] Example 1

[0042] This embodiment is a project for the resource utilization and disposal of waste drilling mud from a drilling platform. The waste mud is polysulfonate waste mud. After homogenization at a stirring intensity of 120 rpm, the waste mud is pumped into a degumming tank. 3 wt% aluminum sulfate is added at a stirring intensity of 90 rpm and the mixture is stirred for 20 minutes. After degumming and destabilizing, the waste mud is pumped into a plate and frame filter press for solid-liquid separation. A portion of the filtrate is recycled back into the homogenizing tank at a ratio of 1:10. The remaining filtrate is pumped into the first conditioning tank, and 2 wt% sodium carbonate is added under a stirring intensity of 90 rpm. After stirring and reacting for 40 min, it is pumped into a centrifuge to remove the precipitate. The filtrate after removing the precipitate is pumped into the second conditioning tank, and 1 wt% potassium polyacrylamide is slowly added using a screw conveyor dry powder feeder under a stirring intensity of 90 rpm. The dosing rate should be controlled at 1 kg / min. After stirring and reacting for 3 h, the drilling circulation slurry is obtained. A portion of the drilling circulation slurry is recycled back into the first conditioning tank at a ratio of 1:100, and the remainder is transported to the mud circulation tank for reuse.

[0043] Example 2

[0044] This embodiment describes a waste drilling mud recycling project for a drilling platform. The treated material is polysulfonate waste drilling mud. After homogenization at 90 rpm, the waste mud is pumped into a degelatinizing tank. 2 wt% polyaluminum chloride is added at 60 rpm, and the mixture is stirred for 10 minutes. After degelatinization and destabilization, the waste mud is pumped into a plate and frame filter press for solid-liquid separation. A portion of the filtrate is recycled back to the homogenizing tank at a 1:10 ratio. The remaining filtrate is pumped into a first conditioning tank, where 0.5 wt% sodium hypotriacetate is added at 60 rpm, and the mixture is stirred. After 30 minutes, continue pumping into the centrifuge to remove the precipitate. The filtered liquid after removing the precipitate is pumped into the second conditioning tank. Under a stirring intensity of 60 rpm, 0.5 wt% of vinyl monomer multi-component copolymer is slowly added using a screw-type quantitative dry powder feeder. The addition rate should be controlled at 1.25 kg / min. The reaction is stirred for 2 hours to obtain the drilling circulation slurry. A portion of the drilling circulation slurry is recycled back into the first conditioning tank at a ratio of 1:200, and the remainder is transported to the mud circulation tank for reuse. The vinyl monomer multi-component copolymer is PAC-141.

[0045] Example 3

[0046] This embodiment describes a waste drilling mud resource utilization project for a drilling platform. The treated material is polymer waste drilling mud. After homogenization at 120 rpm, the waste mud is pumped into a degelatinizing tank. At 90 rpm, 2 wt% calcium chloride and 2 wt% calcium oxide are added, and the mixture is stirred for 15 minutes. After degelatinization and destabilization, the waste mud is pumped into a plate and frame filter press for solid-liquid separation. A portion of the filtrate is recycled back to the homogenizing tank at a 1:5 ratio; the remaining filtrate is pumped into the first conditioning tank, where it is further treated at 90 rpm. Add 1 wt% diethylenetriaminepentaacetic acid pentasodium, stir and react for 30 min, then continue pumping into a centrifuge to remove the precipitate. The filtered liquid after removing the precipitate is pumped into the second conditioning tank. Under a stirring intensity of 90 rpm, slowly add 1 wt% carboxymethyl cellulose using a screw-type quantitative dry powder feeder. The dosing rate should be controlled at 1 kg / min. Stir and react for 3 h to obtain the drilling circulation mud gel. Part of the drilling circulation mud gel is recycled back to the first conditioning tank at a ratio of 1:150, and the remainder is transported to the mud circulation tank for reuse.

[0047] Example 4

[0048] This embodiment describes a waste drilling mud resource utilization project for a drilling platform. The treated material is polymer waste drilling mud. After homogenization at 90 rpm, the waste mud is pumped into a degelatinizing tank. 2 wt% calcium chloride is added at 60 rpm, and the reaction is carried out for 15 minutes. After degelatinization and destabilization, the waste mud is pumped into a plate and frame filter press for solid-liquid separation. A portion of the filtrate is recycled back to the homogenizing tank at a 1:10 ratio, and the remaining filtrate is pumped into the first conditioning tank, where 0.5 wt% calcium chloride is added at 60 rpm. After stirring and reacting with % diethylenetriaminepentaacetic acid pentasodium for 30 minutes, the mixture is pumped into a centrifuge to remove the precipitate. The filtered liquid after removing the precipitate is pumped into the second conditioning tank. Under a stirring intensity of 60 rpm, 0.5 wt% carboxymethyl cellulose is slowly added using a screw-type quantitative dry powder feeder. The dosing rate should be controlled at 1 kg / min. The mixture is stirred and reacted for 3 hours to obtain the drilling circulation mud gel. A portion of the drilling circulation mud gel is recycled back to the first conditioning tank at a ratio of 1:150, and the remainder is transported to the mud circulation tank for reuse.

[0049] Example Performance Evaluation

[0050] The gel solutions formed in Examples 1, 2, 3, and 4 were compared with water. 5% (mass fraction) of drilling field slurry-mixing clay and 0.2% (mass fraction) of soda ash were added to each solution. The mixtures were stirred at 11,000 rpm for 20 minutes and then cured in a sealed container at 25±1℃ for 24 hours. Following the recommended methods in the current standard GB / T 16783.1-2020 "Field Testing of Drilling Fluids for Petroleum and Natural Gas Industry - Part 1: Water-based Drilling Fluids", the room temperature rheological properties and low-temperature, low-pressure API filtration loss of the suspensions were measured using a six-speed rotational viscometer and a medium-pressure filtration loss meter. The experimental results are shown in Table 1.

[0051] Table 1. Comparison of the performance of drilling slurries prepared by reusing filtrate, water, and the gel solutions formed in Examples 1-4.

[0052]

[0053] As can be seen from Table 1, the drilling slurries prepared with waste mud debonding and filtration water in Examples 1-4 showed that, compared with drilling slurries prepared with clean water, the differences in system stability indicators such as rheological properties (AV, PV, YP) ​​and API water loss of the drilling slurries prepared in the examples were within 5%. This indicates that the drilling slurries prepared with waste mud debonding and filtration water can replace clean water for reuse in drilling projects.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A process for preparing drilling circulating slurry, characterized in that, Includes the following steps: The waste mud was homogenized. A desiccant was added to the homogenized waste sludge to react, and the filtrate was obtained after the reaction was completed. The filter fluid is conditioned to obtain drilling circulating slurry.

2. The preparation process of drilling circulating slurry as described in claim 1, characterized in that: The process of conditioning the filtrate to obtain drilling circulation slurry includes: adding an ion removal agent to the filtrate for reaction, centrifuging the reacted filtrate, adding a conditioning agent to the centrifuged filtrate for reaction, and obtaining drilling circulation slurry.

3. The preparation process of drilling circulating slurry as described in claim 1, characterized in that: The separated filtrate is recycled back into the homogenization process, with the volume ratio of recycled filtrate to waste sludge being 1:5-10.

4. The preparation process of drilling circulating slurry as described in claim 1, characterized in that: During the homogenization process, the waste sludge is stirred at a rate of 90 rpm to 120 rpm.

5. The preparation process of drilling circulating slurry as described in claim 1, characterized in that: The de-gelling agent is at least one of aluminum sulfate, polyaluminum chloride, calcium chloride, and calcium oxide, and the amount of de-gelling agent added is 2%-4% of the mass of the waste sludge after homogenization treatment.

6. The preparation process of drilling circulating slurry as described in claim 1 or 5, characterized in that: The degreasing agent is added while stirring at a speed of 90 rpm to 120 rpm.

7. The preparation process of drilling circulating slurry as described in claim 2, characterized in that: The ion removal agent is at least one of sodium carbonate, sodium hypotriacetate, and sodium diethylenetriaminepentaacetate, and the amount of ion removal agent added is 0.5%-2% of the mass of the filtrate.

8. The preparation process of drilling circulating slurry as described in claim 2, characterized in that: The conditioning agent is at least one of potassium polyacrylamide, vinyl monomer multi-element copolymer and carboxymethyl cellulose, and the amount of conditioning agent added is 0.5%-1% of the mass of the filtrate after centrifugation.

9. The preparation process of drilling circulating slurry as described in claim 8, characterized in that: The dosage rate of the conditioning agent is 1 kg / min to 1.25 kg / min.

10. The preparation process of drilling circulating slurry as described in claim 2, characterized in that: The drilling circulating slurry is reintroduced into the conditioning process, and the volume ratio of the reintroduced drilling circulating slurry to the filter fluid is 1:100-200.

11. A drilling circulating slurry, characterized in that: It is prepared using the drilling circulating slurry preparation process described in any one of claims 1-10.

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