Study on the Separation Technology of HGS and Its Effect
143
Figure 4 showed the installation diagram of experimental equipment. All the HGS
and drilling fluid before injecting into the simulated drill pipe were in tank 1. The
separated HGS and part of the drilling fluid flowed into tank 2, and the mixture of the
rest of the drilling fluid and the remaining HGS were in tank 3. During the experiment, the
opening, closing and the frequency of the pump as well as the opening of the inlet valve
2 were adjusted through screen 1 of the control cabinet. And, then the frequency of the
pump will be displayed in the screen 2 of the control cabinet. Meanwhile, the diameter
of HGS will be changed from 0.3 mm to 0.7 mm so as to determine the separation
efficiency of HGS under different conditions.
2.2 The Results Analysis of Separation Experiment
As can be seen from Fig. 5, 6, 7, 8, 9 and Fig. 10, the variation rule of the separation
efficiency with the diameter of HGS and the frequency of the pump was studied respectively when the opening degree of the inlet valve 2 is certain. With the increase of the
diameter of HGS, the centrifugal force that the HGS was subjected to in the separator
increased, so the separation efficiency first increased. Then, with the further increase of
the diameter, the surface area of HGS in contact with the drilling fluid was also increased.
Due to the influence of viscosity, the viscous force that HGS was subjected to increased
significantly, so the efficiency of the separator started to decline. If the diameter of HGS
remains unchanged, the separation efficiency will increase with the augment of the pump
frequency. So the greater centrifugal force was generated in the separator, which was
more conducive to the separation of HGS, so the separation efficiency was significantly
improved. However, when the pump frequency reached critical frequency 40 Hz, the separation efficiency began to decrease slightly, and when it reached 45 Hz, the separation
efficiency showed a significant decrease. This was because when the pump speed was
too high, it was a short time for the mixed fluid of HGS and drilling fluid to pass through
the separator that made the HGS enter the lower exit of the simulated drill string before
they could be separated, and finally leading to the decrease of separation efficiency. By
comparing the variation trend from Fig. 5, 6, 7, 8, 9 and Fig. 10, it can be seen from
the figures that, when the opening degree of the inlet valve 2 remained unchanged, the
variation trend of separation efficiency has an uptrend and a downtrend with different
diameter of HGS.
As the opening degree of the inlet valve 2 increased from 15° to 40°, if the diameter of
HGS remained unchanged, the separation efficiency difference in the downtrend section
was gradually narrowed under different pump frequencies, while the same that in the
uptrend section is not obvious.
As the Fig. 11, 12, 13 and Fig. 14 respectively shown, the influence of the diameter
of HGS and the opening of the inlet valve 2 on the separation efficiency was investigated
when the pump frequency is constant. When the opening of the inlet valve 2 remained
constant, the separation efficiency varied with the HGS diameter in a manner similar
to that described above. When the diameter of HGS remains unchanged, the separation
efficiency gradually increases with the increase of the opening degree of the inlet valve
2. When the opening degree of the inlet valve reaches critical value 40°, the separation
efficiency no longer increases significantly. Because the opening degree of the valve 2
can adjust the pump rate of the mixed fluid of HGS and drilling fluid in the inlet, the
143
Figure 4 showed the installation diagram of experimental equipment. All the HGS
and drilling fluid before injecting into the simulated drill pipe were in tank 1. The
separated HGS and part of the drilling fluid flowed into tank 2, and the mixture of the
rest of the drilling fluid and the remaining HGS were in tank 3. During the experiment, the
opening, closing and the frequency of the pump as well as the opening of the inlet valve
2 were adjusted through screen 1 of the control cabinet. And, then the frequency of the
pump will be displayed in the screen 2 of the control cabinet. Meanwhile, the diameter
of HGS will be changed from 0.3 mm to 0.7 mm so as to determine the separation
efficiency of HGS under different conditions.
2.2 The Results Analysis of Separation Experiment
As can be seen from Fig. 5, 6, 7, 8, 9 and Fig. 10, the variation rule of the separation
efficiency with the diameter of HGS and the frequency of the pump was studied respectively when the opening degree of the inlet valve 2 is certain. With the increase of the
diameter of HGS, the centrifugal force that the HGS was subjected to in the separator
increased, so the separation efficiency first increased. Then, with the further increase of
the diameter, the surface area of HGS in contact with the drilling fluid was also increased.
Due to the influence of viscosity, the viscous force that HGS was subjected to increased
significantly, so the efficiency of the separator started to decline. If the diameter of HGS
remains unchanged, the separation efficiency will increase with the augment of the pump
frequency. So the greater centrifugal force was generated in the separator, which was
more conducive to the separation of HGS, so the separation efficiency was significantly
improved. However, when the pump frequency reached critical frequency 40 Hz, the separation efficiency began to decrease slightly, and when it reached 45 Hz, the separation
efficiency showed a significant decrease. This was because when the pump speed was
too high, it was a short time for the mixed fluid of HGS and drilling fluid to pass through
the separator that made the HGS enter the lower exit of the simulated drill string before
they could be separated, and finally leading to the decrease of separation efficiency. By
comparing the variation trend from Fig. 5, 6, 7, 8, 9 and Fig. 10, it can be seen from
the figures that, when the opening degree of the inlet valve 2 remained unchanged, the
variation trend of separation efficiency has an uptrend and a downtrend with different
diameter of HGS.
As the opening degree of the inlet valve 2 increased from 15° to 40°, if the diameter of
HGS remained unchanged, the separation efficiency difference in the downtrend section
was gradually narrowed under different pump frequencies, while the same that in the
uptrend section is not obvious.
As the Fig. 11, 12, 13 and Fig. 14 respectively shown, the influence of the diameter
of HGS and the opening of the inlet valve 2 on the separation efficiency was investigated
when the pump frequency is constant. When the opening of the inlet valve 2 remained
constant, the separation efficiency varied with the HGS diameter in a manner similar
to that described above. When the diameter of HGS remains unchanged, the separation
efficiency gradually increases with the increase of the opening degree of the inlet valve
2. When the opening degree of the inlet valve reaches critical value 40°, the separation
efficiency no longer increases significantly. Because the opening degree of the valve 2
can adjust the pump rate of the mixed fluid of HGS and drilling fluid in the inlet, the