Background
There is a steady increase in output of ChangQing Oil Field located in Gansu province of China, which gives an urgent challenge to operators of some gathering pipelines. The conditions of the pipelines and crude oil properties are tabulated as follows:
| Item | Pipeline and oil | |
|---|---|---|
| YanHewan to YangShan | JingErlian to MaLing | |
| Pipeline length [km] | 37.2 | 193.5 |
| Pipe diameter [mm] | 207 | 158/209 |
| Pipeline fall [m] | 64.7 | 158 |
| Pump station number | 2 | 5 |
| Flow rate range [bpd] | 30,000~40,000 | 12,800~14,300 |
| Wax [%] | 16.7 | 15.5 |
| Asphaltene [%] | 36.6 | 6.03 |
| Colloid [%] | 0.9 | 0.58 |
| Density [kg/m3] | 844 | 850 |
| Water [%] | <0.5 | <0.5 |
| Gel point [°C] | 22 | 23 |
Field Test
After all determinations of actual conditions were made, a ten-day test was conducted on two segments of the pipeline during April 11 to 20 in 2001 to verify the estimates above .Soon after all analyses and testing were completed, Changqing Oil Field confirmed the data and placed an order on EP-W203 DRA. So far EP-W203 DRA has been used on the gathering pipelines for more than six months and just 10ppm injection dosage would reduce drag by 20% at each site, saving totally US$8'500 a day.
Objectives
More than a few employees of this pipeline were surprised when it was estimated that by using EP-W203 DRA, there will be a throughput increase of 20~50%. After accounting for the cost of EP-W203DRA, net savings could totally be more than US$3,000,000 a year in energy, mechanical, maintenance and other costs associated with operating a large pipeline system. It simply sounded too good to be true. Essentially, the challenge issued to us was simple: prove it!