Monthly Archives: February 2016

Maintenance of sand pump bearing by grease

Bearing is widely used in sand pump, shale shaker, centrifuges and other equipments, it is vulnerable. So it can prolong the service life of wearing parts by paying attention to bearing’s  maintenance.

Pump bearings used in the sand pump has been filled with lubricating grease at the place of pump manufacturer in accordance with the rule, so the sand pump not need to be filled with grease at the working condition of low speed, low temperature (as opposed to 120 centigrades)  in process of being used. When the pump under the working conditions of high load high temperature (as opposed to 120 centigrades), the bearings must be regular added with grease to ensure the service life. To the pumps which meed to be added with grease regularly, you must select the  lubricating grease that are compatible with the original one, or the lubrication effect will eb poor and it will affect the service life of the bearing.

DC solids control bearing

Tools for adding grease: standard manual filling gun. Replenishment cycle and the amount of filling: the pump for round the clock used, fill the grease once a week, and five shots each bearing and each time. For the pump that work eight hours day and night, fill it with grease once every three weeks, and five shots for each bearing each time. And for the pump that work for round the clock, fill it with monthly and twenty shots everytime is okay also.

Scientific selection of hydrocyclone for desander and desilter

Abrasive resistance is the mainly quality target of the cyclone, and the separation size which also called D50 is the mainly performance of hydrocyclone, the lower the D50, the better the separation efficiency of the cyclone. In the desander, desilter configuration should pay attention to the particles separation range not only have a certain distance, but also have a certain degree of overlap.

According to the classification standard and separating size of hydrocyclone. The inner diameter of the cylindrical casing for diameter 150 – 300 mm, separation size of 74 – 44μm of the water cyclone were drilling fluid desander; the inner diameter of the cylindrical casing for phi 100-150, the separation granularity for 44 – 15μm of the water cyclone for desilter. But the separation size of the desander and desilter in the field maybe colse (drilling fluid desander for 20 – 50μm, desilter for 45 – 15μm), after the drilling fluid processed by desander then it processed by desilter, resulting in the desilter can’t have effect on removing solid particles . The main reason for the above phenomenon is that the manufacturing level of the cyclone is not up to the requirements, and the effect can not be hit by the drilling process. So many users choose the macthing scheme of 2 sets of drilling fluid desander instead of 1 set of drilling fluid desander and one desilter.

desander1

Some users simply install second sets of drilling fluid desander in place of desilter mounted, the process will not change. This method is not desirable, since the performance parameters of the two sets of drilling fluid desander are the same, it should be using parallel process, to mutual standby or fast drilling in increasing the processing capacity of the drilling fluid. But for the well with high requirements of the drilling fluid performance, the reasonable supporting scheme is still supporting one set of drilling fluid desander one desilter, using the series process.

In the selection the desander and mud desilter should choose products with different separation particle size range, such as desander separation size range for 40 – 60μm, separation size of desilter s for 15 – 45μm, then it can achieve better treatment effect.

Pump casing and impeller of drilling centrifugal pump

Impeller and the pump shell of centrifugal pump. Ordinary centrifugal pump’s impeller has three types of open, semi open and closed.

When the impeller of the centrifugal pump has no front and back cover, and the floatboard is fully exposed, it is called the open type. Only back plate, called semi open type. They are used to transport slurry, viscous or solid particles suspended in the liquid, and it is not easy to plug, but the liquid is prone to backflow  in the movement between the blades, so the efficiency is low. The impeller that has both the front and back plate is called closed impeller, the sand pump adopts open impeller.

Hisilicon K3

The pump shell is the shell of the pump body, which surrounds the rotating impeller. Pump shell forms a volute passageway whose section area expand gradually  around the impeller, so it is often referred to as the volute.

The direction of rotation of the impeller in the shell is the direction which is gradually enlarged along the volute passageway. The more close to the outlet, the more liquid the shell is exposed, so the cross-sectional area of the passage must be increased gradually.

More  important is that, the liquid throwned with a high speed around the impeller reduce its speed in the channel gradually, so that a large part of the kinetic energy is changed into pressure energy, this both improve the fluid outlet pressure, and reduce the energy loss inside the pump body caused by the exorbitant liquid flow speed.

Therefore, the pump shell is not only the shell of the pump, the collection of liquid, but aslo a power conversion device itself.

Maintenance techniques for drilling mud agitator

Mud agitator is a liquid-solid mixing equipment, which is mainly used in drilling mud circulation system in oil field. Mud agitator is mainly used for drilling fluid mixing, make the drilling fluid in the circulating tank produced circumferential, radial flow and axial flow to prevent solid particles in drilling fluid deposite in the circulatory system, and make the performance  of circulating drilling fluid is stable.

SONY DSC

How to maintain the mud mixer:

  1. Before starting, check the connecting parts to see whether there is a loose phenomenon, tighten it if have.
  2. When testing the mud agitator, the main observation of the whole machine is running smoothly, whether the noise is too large, stop to check it imediately if there are some abnormal phenomenon. After the trouble is excluded, mud agitator can be put into normal operation.
  3. The staff should check the reducer through the oil standard to see if the lubricating oil in the body of gear box is added enough, if the lubricating oil is not enough, the same grade of oil must be added in.
  4. Check the sealing condition of oil drain plug to see whether there is oil spillings. If the oil leakage phenomenon happen, you must tighten the drain plug.
  5. After starting to use the mud agitator, you should discharge all the lubricating oil which are in the gear box at most five days and clean up the inside of gear box, change it with clean oil and replace it every 6 months.
  6. After the running of the mud agitator is over, if it won’t be in use for a long time, you should wash and clean up the mud in the impeller that on the mud agitator.

Points for installation of centrifugal pump

  1. To master the methods of selecting the specifications, rotating speed and the impeller diameter of sand pump comprehensively, or let the professionals to complete it. Never change the impeller diameter without inspections or suggestions of professional and technical personnel and don’t turn the impellers on the site, otherwise the pump’s balance will be damaged.
  2. Each pump should be have the independent suction line especially we should two pump export pipeline parallel together, parallel running pump displacement of only a slight increase, so as to avoid the waste, may also be caused by solid control equipment operation of other problems.
  3. When installing the sand pump, there is a suction pipe on the pump which is filled with fluid, there should be deep enough liquid in inhalation tube to prevent vortex and gas lock, it is needn’t or not recommend that install a bottom valve on the suction pipe.

    sand pump

  4. Be sure that the motor has enough power to meet the requirements transport the maximum drilling fluid density at the maximum flow rate.
  5. It is suggested that a pressure gauge is installed between the discharge pipe and the first valve of sand pump, when the valve is closed, the pressure gauge reading can be diagnosed and the performance of the pump is evaluated.
  6. Make sure that the rotating direction of impeller is correct. Centrifugal pump can pump the fluid, even if in the reverse rotation, but this time the pressure head of the centrifugal pump is lower than the normal operation. The pressure gauge between the pump and the first valve will help to find the error, and covert the two wiring on the control panel can change the rotating direction.

Major process of installation of decanter centrifuge

Drilling fluid solids control centrifuge generate centrifugal force of high speed ratation by the rotor of motor which can accelerate the settling velocity of the solid particles in the liquid phase, and the solid particles with different sedimentation coefficient and buoyancy density are separated. The slag pushing job of the drilling fluid solids control centrifuge is accomplished by the propeller.

Under the action of the differential, a certain speed difference formed between the screw propeller and the roller, the solid particles that have been settled to the cylinder wall are scraped away from the cylinder wall and then pushed to a small end of the roller by the helical blades, and are dehydrated during propulsion process, solids particles reach the sand spray nozzle finally and are thrown ot of the roller, then the four-class treatment of drilling mud solids control is completed.

 

Centrifuge-


Installation procedure of drilling fluid solids control centrifuge:

1. The drilling fluid solids control centrifuge should be firmly installed at the place where is far from the entrance of the drilling pump in order to ensure that the recovery of liquid phase can be fully stirred.

2. It should be sure that the drilling fluid solids control centrifuge is fixed firmly, the four legs of the bracket should be fixed on the position of the tank surface that with a supporting beam position.

3. It should be ensured that the sand drain tank can be extended out to the tank to make it easy to drain sand during the installation of drilling fluid solids control centrifuge , and connect the water supply line well on the sand drain tank to ensure sand draining smoothly.

4. The drilling fluid pump should be installed in the proper position after cyclone desander and mud desilter, and connect the feeding pipe to the inlet pipe joint right.

5. Connect the flushing water supply pipe and shunt tube on the inlet pipe and box body right.

6. Turn on thepower supply. There should be switch controling between the control box to the power supply of the drilling fluid solids control centrifuge to ensure the safety of maintenance.

 

How to make good condition of jet mud mixer

In order to make the installation and use of the jet mud mixer more efficient, we should pay attention to several problems:

1 Selecting the  jet mud mixer which is suitable for drilling fluid system.

2 Keep the distance between the pipe line and the hopper as short and straight as possible.

3 Use new and clean spare parts to reduce friction loss.

4 Working table should be installed and fixed near the funnel to support the materials in a bag.

5 As well as the maintenances of other drilling equipments, regular maintenances and inspections of the drilling funnel shall be maintained.

jet mud mixer

 

If the injection function of the nozzle is not up to standard, the following contents shall be checked :

1 in normal discharged pressure head, determine whether the pump can provide enough drilling fluid, and check the pressure gauge on the upper reaches of the funnel of jet mud mixer.

2 When the device is closed, the hopper and valve are removed from the three – way pipe, and the live joint is installed on the upper of the funnel, and check to determine whether there is corrosion or whether there is an object – blocking gas lift pipe.