Monthly Archives: October 2012

Solid control system in HDD industry

hless pipeline directional drilling crossing are distance surface 15 ~ 30 m stratum, lithology is loose, surface water saturation high alluvial and deposition and formation of sand, clay and mixture, belong to not rock formation, easy to collapse, easy string leakage, a few areas including JiangJieShi, easy cause sticking or card tube.
And because of directional through construction of the aperture ratio oil drilling of aperture, mud displacement is small, the annular clearance is large, continuous proportioning homework, reflux ability is poor, be in so trenchless directional drilling mud returns have the following features:
1. Mud contains large amount of sediment;
2. Mud viscosity high;
3. Mud supply is continuous, the return is discontinuity, return out of the mud is not enough to meet the requirements of drilling,
4. Through on both sides of the return to mud.

Due to the large diameter and long directional drilling crossing in our country is developed in recent years. Domestic to mud purification and recovery system is short of the corresponding research, plus large trenchless directional drilling the quantity is less, so often the oil drilling mud purification system simple used in trenchless in directional drilling. Some directional drill equipped with solid control system, the existing problem is:
due to the return of the mud sand content, viscosity, high oil drilling solid control system of the vibrating screen can’t satisfy the requirements, appear running, running mud phenomenon, a large amount of sand mud covered with vibrating screen online, resulting in vibrating screen will not work.
the present domestic not suitable for trenchless directional drilling rate of desander and desilter. Oil drilling solids control equipment general throughput in 200 m3 / h or so, and return to directional drilling mud just drilling pump pump into the mud, part of the therefore need throughput is in commonly 90 m3 / h or so.

the trenchless directional drilling general no mud recycling, the configuration of the mud is pure, the drilling pump wear less, so drill matching drilling pump don’t like oil rig configuration spare drilling pump. Therefore, the present purification and recovery system due to the mud in the tiny sand mud treatment not clean, affect the use of drilling pump.

And DaChuan Machinery in the light of these problems, developed a set of used in trenchless directional drilling crossing mud purification and recycling device, this system process design is reasonable, the system function is complete, advanced performance, can be recycled back to the mud, and preparation works for directional drilling mud, and treatment of mud main performance conforms to the directional drilling crossing engineering construction on its performance requirements, especially solve the previous system in soil layer cannot be solved through the sand, mud and recovery problem, mud materials saved more than 40%. The system mainly advantages are:

device of primary treatment vibrating screen with the engineering of slotted screen, porosity, high strength, for sand content, viscosity high return mud slurry can efficient processing.
the desander and desilter of throughput in 100 m3 or so, suitable for trenchless directional drilling crossing engineering application.
using drilling fluid centrifuge, can remove tiny particles in the system, avoid the drilling pump wear.
using a fast vortex mix slurry device, to ensure the continuity of supply through drilling mud.

the whole device process is reasonable, can realize trenchless directional drilling crossing project of solid phase control, slurry preparation and recovery.

Assembly and Disassembly of the Vertical Sand Pump

Vertical sand pump

1. The pump is of vertical type, and can be used in a slant way within a certain angle range. And the vertical sand pump can be fixed on a pontoon, a floating platform or a fixed pedestal.

2The motor should be provided with a protective cover and the cable interface should be carried out waterproofing process.

3Oil nozzles at the motor seat and the middle section should be filled with oil once in each operation. The pump body should be maintained once every 300 hours. And the motor should be maintained once every three months.

4The main machine of the vertical sand pump should be cleaned and maintained, added with oil to prevent rust, and stored in a dry place when not used. And the main machine of the pump should keep vertical when transported and stored.

Assembly and Disassembly of the Vertical Sand Pump
1While disassembly, the order is motor and coupling firstly – pump shell – adjusting nut – guard plate – pump cover – shaft housing – positioning sleeve – pump seat – motor frame – main shaft – bearing finally. All the disassembled metal parts are cleaned and checked.

2The vertical centrifugal pump shall be assembled in a reverse order compared with disassembly order. The adjusting nut is used to adjust the clearance between the impeller and the guard plate in the assembly. The main shaft should be rotated by hands to make sure that it is not blocked after assembly. And the bearing chamber and the shaft gland chamber should be filled with lubricating grease during assembly.

The main technical parameters of the centrifuge in drilling fluid

The main technical parameters of the centrifuge
Drilling fluid is used in spiral sedimentation centrifuge, the technical parameter is according to the requirements of the separation process and economic benefit principle, overall balance various factors of choice.

Structure parameters
Structural parameters including: drum internal diameter D, drum total length L, drum half Angle a, drum overflow the inlet diameter DI, screw pitch S, pitch bus (spiral surface and the shaft into line) and perpendicular to the shaft section Angle 0, usually 0 = a.
L/D in certain conditions, centrifuge production capacity roughly proportional with D3. According to the diameter of the centrifuge at home and abroad have been series. The requirements of China’s series diameter for: 200450600800100 0 mm, foreign centrifuge series diameter for: 6,8,10,16,20,25,30,40 in.
In the centrifugal force equal conditions, drum diameter is larger, the speed is lower, solid phase particle in the drum inside residence time to grow more, can make the fine solid particles in centrifugal effect sinking down to turn on simulated and be excluded. Drum length is big, solid phase stay for a long time, separation effect is good, for difficult separation to material.
L/D = 3-4
Drum shape have column cone and conical two basic structure. In the drum diameter and length equal, column conical can provide greater internal settlement space, make the solid particles in the drum inside residence time is longer, the separation ability stronger.

Drilling fluid solids control meaning and method

If not solid control of the drilling mud ,what will happen?

Lead to density increases, reduce mechanical drilling rate, shorten bit life.
Into the ground, jam oil and gas channel, go against gas reservoirs.
Filter cake formation to drill torque, wear serious, blocked, sticking
Sand content is high, wear bit, drill, etc., make cost increase.
High viscosity, increase the resistance to flow, reduce the energy utilization
Easy create solid phase particle invasion and chemical pollution
Formation of filter cake thickness, the casing difficulties, influence cementing quality
Lead to sample confounding, electrical measuring adverse, etc., so that information is not accurate

Water dilution method
Add a lot of water, increase the overall product, make the solid content relative to reduce
Faults: increase reserve equipment, waste, performance fluctuation, cause an accident

Replace part of the drilling fluid method
With clear water or to meet the requirements of low solid drilling fluid replace certain volume high solid content of drilling fluid, to reduce the content of solid phase method.

Big pool precipitation

Into the systemic circulation pool, debris, sand in the action of gravity from the drilling fluid separated the settlement method. This method in the field use call common.

Chemical flocculation

Join flocculant with 200-400 m3 big settling pit precipitation
Through the flocculating agent tank, clear the solid phase, for not disperse system.

 mechanical equipment

Use of screening, centrifugal separation principle, and the drilling fluid solid phase particle size and density according to the different separation, the control method of solid content.

SB6*8 Sand pump installation and operation instruction

overview

SB series sand pump is for oil and gas drilling equipment characteristics of the new developed supporting pump, it uses axial suction structure, flow components for antiwear cast iron is applicable to transport corrosive aerosol drilling fluid or other similar conditions of liquid medium, it is desander, desilter, mixed funnel best supporting pump, but also is the ideal mud pump infusion pump, the parameter design give full consideration to the supporting device can work under the optimum condition, the main features are parts of the universality and interchangeability is strong, shaft seal leak less, reliable operation, long service life, easy maintenance.

SB series sand pump have five types: SB6 “* 8”, SB 5 “* 6”, SB3 “* 4 and SB2” * 3 “. Model SB6 “* 8” can match 45 kw, 55 kw, 75 kw, motor, according to user requirements have positive transfer pump and reversal pump six specifications;

Model SB5 “* 6” with 22 Kw, 30 Kw, 37 Kw, 45 Kw motor, a reversal pump four specifications.
Type 4 “* 5” match 15 kw, 22 kw motor, a reversal pump two specifications.
Model 3 “* 4” with 11 kw, 15 kw motor, a reversal pump two specifications.
The former two types of pump the seal is universal.
Reversal pump all appearance and installation dimensions and are turning pump are basic and same, just volute eliminate tube, are turning pump on the left side, reversal pump on the right (from the suction side to see)
Sand pump SB6 “* 8” recommended for 3200 meters above drill supporting the use of sand pump SB5 “* 6” recommended for 2500 meters below the supporting the use of the drilling rig.
SB series sand pump seal use of mechanical seal and composite seal two ways.
SB series sand pump shaft seals use grease lubrication, Bearing the oil lubrication, bearing on both ends of the bearing cover on the grease fitting, bearing can also be used grease lubrication.
SB series sand pump was in climatic conditions extremely bad northern Canada winter and the United States of Alaska for use in the summer after two years, and the results show that, in addition to the normal seal change outside, other maintenance costs very little.

decanting centrifuge in solid control system

Mud treatment with centrifuge can be divided into two types of low and high speeds

At present the application of high and low speed centrifuge not put forward the classification of unity, but according to the solid control system in the role of different, can simply divided into: low speed centrifuge – separating solid particles range of more than 20 um solid phase particles,
High speed centrifuge – separating solid particles range is greater than 5 um of solid particles.

Low speed centrifuge in solid control system of the main purpose is to drilling fluid system in barite and increase solid particles throw in drilling fluid and to recycling, in order to control the density of drilling fluid, and its economic benefits for dilution drilling fluid to control the drilling fluid density method is very obvious.

High speed centrifuge is the rate in low speed centrifuge is concerned, throughput little about five times (about 1.5-6 m3 / h), and can deal with the solid particles is relatively fine, separation contain higher solid phase concentration of drilling fluid result is bad, so must and low speed centrifuge collocation is used. But high speed centrifuge solid phase processing range is just affect drilling fluid viscosity of solid phase range (1-10 um) or so, so for the deep well reduce drilling fluid of shear force, improve the wellbore quality and prevent the downhole accident, high-speed centrifuge effect is very good.

Drilling mud Decanter centrifuge

DCLW series decanter centrifuge adopts centrifugal force to separate solid particles out of     drilling fluid .Different solid or particle have different density and flow speed ,some decanter centrifuge also can separate particles as different size and density ,DCLW decanter centrifuge is widely used in oil and gas drilling ,chemical,foodstuff ,pharmacy ,mineral beneficiation ,water treatment ,etc .Industries.

 

solid control technology

Selective solid phase control technology

Application of selective solid phase control technology, wellhead return drilling fluid by efficient shale shaker is divided into big grain after wet cuttings (> 74 um) and sifting fluid, sifting liquid by hierarchical filter ceding level 3 solid phase, from coarse to fine in turn for coarse cuttings (74-35 um), increase solid phase (35-15 um) and fine cuttings (2-15 um), aggravating solid phase the disperser after scattered back into the drilling fluid system, coarse cuttings and fine cuttings effluent.

So to drilling fluid realize the selective solid phase control, can remove more harmful solid phase, especially grain size less than increase solid phase of harmful solid grain, can greatly improve the mechanical drilling rate, reduce drilling fluid viscosity, lower dilution water, reduce drilling fluid volume.

Drilling fluid online processing technology
In the past only pay attention to the processing of drilling fluid, and ignore the drilling scrap processing, drilling debris directly into mud pool. Each Wells need a mud pit, mud pit area more than 500 m2. Through the wet cuttings online processing, can be divided into the filtrate and dry drilling crumbs, filtrate return to drilling fluid system, stem cuttings are mounted on storage box, centralized treatment and recycling.

Through the cuttings online process can make the cuttings and waste drilling fluid in drilling field do not fall to the ground, and fully recovery available drilling fluid, and tell the mud pit, has obvious economic benefits and huge social benefits.

Drilling fluid reuse technology

A well drill into the waste drilling fluid after general for 100-300 m3. According to the corresponding formation characteristics and the drilling fluid type on these waste carry on the classified management, the available drilling fluid make recycling, which can reduce the total amount of drilling fluid, reduce emissions, the benefit is very obvious.

Of course, the drilling fluid repeated use need a whole process measures, including drilling fluid stability improvement, classification storage, reasonable application and so on several aspects.

The development direction of the solid control system

Solid control system simplification and optimization

Field test shows that, by using efficient shale shaker and frequency of centrifuge new two-stage solid control system, can dispense with desander and desilter, energy-saving effect is obvious.
Also can use hierarchical filter technologies, and thoroughly change the existing solid control system, also can leave out desander and desilter and other equipment.
Using vacuum filtration way, can even save shale shaker, greatly simplify the solid control system, reduce drilling team generator load, optimize mud tank configuration, reduce the transition mud tank quantity, increase the reserve tank quantity, thus obviously improve solid control efficiency, shorten the processing time, increase the safety of drilling.

 

First degassing, then sieve
At present, the wellhead return drilling fluid is often pass shale shaker first , and then further degassing treatment. In the screening process, a large amount of gas overflow, not only increased the risk of vibrating screen points, and seriously damage the operating personnel’s physical health.
The special design of deaerator Settings in the first place, first of all to head back to the drilling fluid for degassing treatment, can reduce drilling fluid of gas content, reduce harmful gas to the harm of human body, reduce the happening of the accident.

Change part of treatment for the whole processing

At present of drilling fluid shale shaker is the only to carry out the whole processing of solids control equipment, to improve drilling fluid solids control level and plays a very important role.

Due to the desander, desilter and centrifuge’s capacity is limited, the following a few grade purification is often part of the operation, in addition there will be part of the drilling fluid through the drilling fluid tank directly into lower storage room and can’t get treatment.
The scene only by increasing the drilling fluid treatment cycle times to improve solid control quality. In fact, each cycle only on drilling fluid used in partial processing, increase cycle times, can increase the proportion of by processing drilling fluid, but reduce the processing efficiency, waste a lot of energy, solid control efficiency is very low.

Through the switch to other processing mode, such as the use of ultra fine vibrating screen or new filter machinery, can increase the productivity, and to realize the whole processing, thus more can guarantee the performance of some advanced downhole tools, and improving the penetration rate.

The development of solids control equipment

At present, the solids control equipment emphasize on the development of foreign solids control equipment performance good, work stability, long life, realized equipment types of standardization and serialization and customization. Foreign solids control equipment level by American BRANDT, SWACO, DERRICK and the company as a representative, the quality and performance of the first in the world.

Foreign pay special attention to solid control system equipment and the optimal allocation of the solid control system efficiency evaluation, and therefore developed drilling fluid solids control expert system.

The use of mud dryer

American petroleum tool co., LTD., solid phase control system is composed of the four sets of shale shaker and two dryer (drying shale shaker) composition. 4 shale shaker and 1 dryer parallel together, borehole fluid returns by drilling fluid distributor shunt to 4 shale shaker and a dryer for processing. They separated from the solid particles again by another a dryer for processing, make the grain further dehydration. Disengage liquid recovery, dry grain be excluded.

Dryer is actually strength super detail mesh shale shaker, screen frame pour 10 degrees, in order to reduce fluid loss. 4 table shale shaker with screen is three dimensional detail waveform screen, instead of the traditional plate type linear screen, three dimensional structure allows gravity force at a solid down into the fold tank, from the trunk area leave, from every fold of the upper solid separation. Therefore increased through the fluid quantity, won’t drown raised portion, and raised portion can increase fluid flow ability. Two layer fine screen cloth attached to a layer of coarse screen cloth above, three layer screen cloth bonding together, make corrugated, then adhesive in the opening of the board. Wave superposition screen area than the ordinary flat screen area has been increased approximately 40%, than flat screen fine about 2-3 mesh size. Processing fluid capacity increased by 70%, and not easy to congestion, the treatment effect is very good.

Mud agitator in solid control system

Agitator: through the impeller agitation, make the drilling fluid of solid particles suspended, avoid settlement of a kind of stirring device.

The function of the agitator is to keep drilling fluid performance is stable, so the agitator impeller discharge fluid must be in tank suspending solid phase up faster than settling velocity and impeller diameter and speed given agitator work volume is certain.

Agitator make its work volume within the drilling fluid circulating agitation one time is called the cycle time and cycle time is commonly 30-90 s. in solid control system, placed shale shaker, etc of the drilling fluid solids control single tank and drilling pump on tank should take little value, to ensure that the drilling fluid performance stability.

Usually take the cycle time for 60 s as setting agitator number of basis.
Agitator specifications are as follows:

JBQ series mud agitator is an equipment to mix solid and gas drilling mud process ,mineral working site ,etc. mud system .This type agitator holding simple structure ,large bearing strength ,lower noise ,more durable .It prevent solid sediment and maintain drilling fluid property.

Type JBQ2.2 JBQ5.5 JBQ7.5 JBQ11 JBQ15
Power 2.2KW(3.0hp) 5.5KW(7.5hp) 7.5KW(10hp) 11KW(15hp) 15KW(20hp)
Rotate Speed 60r/min
Shaft Length Decided by the depth of the tank.
Number Of Impeller Layers Two layers or monolayer
Impeller Diameter Decided by the inside diameter of the tank.
Remarks If the length of impeller shaft is beyond 1800mm, Centralizer set is required.