- Industry: Oilfield Production
- Products Used: Complete Range of Oilfield Demulsifier's
- Location: Middle East Client
THE PROPOSITION
The client operated field in the Middle East which produces crude with not only a heavy API but also a significant water cut. As such it is essential that the correct Oilfield Demulsifier is employed onsite, in order to remove any water contained within the crude oil, before it is sent to refinery.
Chemiphase were invited to carry out Demulsifier bottle testing onsite, in order to determine the correct demulsifier blend to be applied onsite.
Well Information
The wells to be tested were from two separate points and would represent one heavy sample and one light sample of crude oil. This is in order to replicate the field conditions.
The crude oil at the well head has an API of 12. This crude oil is fed into a production manifold where a secondary, lighter crude is blended into it. This lighter crude has an API of 34 and serves to raise the combined crude to an API of 17. After this point the chosen demulsifier is added and the combined crude and demulsifier is sent to one of three retention tanks. The free water is constantly removed from these retention tanks, until such time as the tanks become full of crude oil. At this point the retention tanks are shut in for 24 hours in order for the demulsifier to remove any water from the crude oil.
During the demulsifier testing the crude oil would be supplied in the form of one heavy sample and one light sample.
Chemiphase Demulsifier Samples
Chemiphase supplied 34 samples of demulsifier bases. These were chosen for their proven ability with heavy crude oils around the world. These were a selection of droppers, treaters, desalters and hybrid chemicals. The samples that were supplied and available for testing were 'ready to use' products and required no blending with solvents. This was to ensure consistency in the samples used for bottle testing and to ensure repeatability.
The full list of Chemiphase demulsifiers that were tested on the client's crude can be found in table 3.0.1
Non Chemiphase Demulsifier Samples
Alongside the Chemiphase demulsifier samples, three other third party demulsifiers were supplied. These were intended to act as a comparison against the Chemiphase samples and in order to show the effectiveness of the Chemiphase products.
The samples were supplied by the client and included "Competitor A," "Competitor B," and "Competitor C."
Bottle Test Method
It was essential that the bottle test method accurately represent the field conditions. The crude oil that is retained in the retention tanks and is subject to the demulsifier, is a blend of the heavy crude oil and a lighter crude oil, intended to raise the overall API to aid in demulsification.
The bottle testing was carried out on the heavy crude oil and light crude oil mixed in a 4:1 ratio of heavy to light. This was mixed in the lab using the crude oil samples supplied.
The bottle testing was carried out using 140ml clear glass sample bottles with clear volumetric markings on the bottles. Each bottle was filled with 100ml of the crude sample and dosed with 500ppm of the demulsifier.
The samples were placed in a water bath at 50 degC and allowed 24 hours for the separation to occur.
The samples were noted for the amount of water drop out, amount of basic solid drop out, clarity of water and sharpness of the oil water interface.
|
Chemiphase |
|
Function |
Suitability |
||||
|
Demulsifier |
RSN |
Dehydrator |
Coalescer |
Hybrid |
All Round |
Heavy |
Environmental |
|
D- 0601 |
15 |
Y |
|
|
|
Y |
|
|
D- 0602 |
11 |
Y |
|
|
|
Y |
|
|
D- 0603 |
17 |
|
|
Y |
|
Y |
Y |
|
D- 0604 |
8 |
|
Y |
|
|
Y |
|
|
D- 0605 |
7 |
Y |
|
Y |
|
Y |
Y |
|
D- 0606 |
19 |
Y |
|
|
|
Y |
|
|
D- 0607 |
17 |
Y |
|
|
|
Y |
|
|
D- 0608 |
6 |
Y |
|
|
|
Y |
|
|
D- 0609 |
8 |
Y |
|
|
|
Y |
|
|
D- 0610 |
23 |
Y |
|
|
|
Y |
|
|
D- 0611 |
11 |
Y |
|
|
|
Y |
|
|
D- 0612 |
21 |
Y |
|
|
|
Y |
|
|
D- 0613 |
18 |
|
Y |
|
|
Y |
|
|
D- 0614 |
20 |
Y |
|
|
|
Y |
|
|
D- 0615 |
7 |
|
|
Y |
|
Y |
|
|
D- 0616 |
6 |
|
|
Y |
Y |
|
|
|
D- 0617 |
20 |
Y |
|
|
Y |
|
|
|
D- 0618 |
16 |
Y |
|
y |
Y |
|
|
|
D- 0619 |
6 |
|
Y |
|
Y |
|
|
|
D- 0620 |
21 |
Y |
|
y |
Y |
|
|
|
D- 0621 |
21 |
Y |
|
y |
Y |
|
|
|
D- 0622 |
8 |
|
|
Y |
|
|
Y |
|
D- 0623 |
15 |
|
|
y |
|
|
Y |
Remaining Water Centrifuge Test Method
Once the bottles had been subjected to 24 hours in the water bath a centrifuge test was carried out in order to determine the total water remaining in the crude samples. This test involved a two stage process.
- The centrifuge test was carried out using 12ml clear glass test tubes with clear volumetric markings. Each test tube was filled with 5 ml of toluene to which a further 5 ml of the crude oil that was to be tested was added.
- The first stage of the test involved centrifuging the samples at 1600rpm for 5minutes. The samples were examined for the amount of water drop out, amount of basic solid drop out, clarity of water and sharpness of the oil water interface. These figures were recorded and the samples moved on to the second stage of the centrifuge test.
- The second stage of the centrifuge test involved introduction of 'knock out drops' to the samples. This was in the form of High strength Knock Out Drops," samples. Two drops of the High strength Knock Out Drops," were added to each sample, the samples were then centrifuged at 1600rpm for a further 5 minutes. The samples were examined for the amount of water drop out, amount of basic solid drop out, clarity of water and sharpness of the oil water interface.
Bottle Testing- Demulsifier Bases
The initial testing involved bottle testing each demulsifier base in order that we could establish the best combination of droppers, treaters, desalters and hybrids.
The bottle test was carried out for each one of the 34 Chemiphase samples along with one blank sample, one sample of the Competitor A and one sample of the Competitor B, as detailed above.
Bottle Testing- Demulsifier Bases- First Round Results
*Water Clarity and Interface are based on a scale of 1-5 with five being the highest and most desirable.
|
Sample |
% H2O Drop Out |
% BS Drop Out |
Water Clarity |
Interface |
|
BLANK |
0 |
0 |
NA |
NA |
|
COMPETITOR A |
9.0 |
0 |
2 - Multiple Large oil droplets in water phase |
2 - Poor, brown opaque (2.5%) |
|
COMPETITOR B |
5.5 |
0 |
2 - Multiple Large oil droplets in water phase |
2 - Poor, brown opaque (1.0%) |
|
Chemiphase D0602 |
2.5 |
0 |
4 - Good, few small oil droplets noticeable |
3 - Quite defined, Ragged interface |
|
Chemiphase D0606 |
5.5 |
0 |
3 - Opaque but oil free |
4 - Highly defined |
|
Chemiphase D0607 |
1.5 |
0 |
4 - Good, few small oil droplets noticeable |
3 - Quite defined, Ragged interface |
|
Chemiphase D0610 |
1.0 |
0 |
3 - Looks clear although very small drop |
3 - Good interface |
|
Chemiphase D0613 |
1.0 |
0 |
3 - Looks clear although very small drop |
3 - Good interface, very small drop |
|
Chemiphase D0618 |
2.0 |
0 |
2 - Multiple Large oil droplets in water phase |
2 - Poor, Ragged interface |
|
Chemiphase D0623 |
2.0 |
0 |
2 - Light brown in colour |
2 - Poor, Ragged interface |
|
Chemiphase D0633 |
7.5 |
0 |
5 - Very Clear Water |
5 - Very Sharp |
|
Chemiphase D0634 |
3.0 |
0 |
5 - Very Clear Water |
4 - Sharp, slight ragged |
The initial testing showed that the Competitor A product performed the best; however the Competitor B product performed in a similar manner to that of the individual Chemiphase Bases at 5.5 % water drop.
Centrifuge Testing- Demulsifier Bases- First Round Results
The samples identified above as being suitable for the second round of testing were tested for remaining water content via the centrifuge test, as outline above.
|
Sample |
Without Knock out Drops (%) |
With Knock Out Drops (%) |
Difference (%) |
|
BLANK |
0 |
0.3 |
0.3 |
|
Competitor A |
0 |
0.2 |
0.2 |
|
Competitor B |
0 |
1.0 |
1.0 |
|
Chemiphase D0633 |
0.5 |
0.5 |
0.0 |
|
Chemiphase D0606 |
3.0 |
3.0 |
0.0 |
|
Chemiphase D0618 |
2.0 |
2.0 |
0.0 |
|
Chemiphase D0623 |
2.0 |
2.0 |
0.0 |
|
Chemiphase D0613 |
0.5 |
0.75 |
0.25 |
Bottle Testing- Demulsifier-Second Round Results
Once the correct Chemiphase bases were established, the bases were combined in order to find the most suitable combination of droppers and treaters. The Chemiphase products were combined in the following way.The samples were tested as per the above method and the results were recorded after 24 hours in the water bath.
|
Set A |
|
Set B |
||
|
Sample Name |
Products |
|
Sample Name |
Products |
|
A1 |
D0602 + D 0604 |
|
B1 |
D0606 + D 0604 |
|
A2 |
D0602 + D 0613 |
|
B2 |
D0606 + D 0613 |
|
A3 |
D0602 + D 0618 |
|
B3 |
D0606 + D 0618 |
|
A4 |
D0602 + D 0623 |
|
B4 |
D0606 + D 0623 |
|
Set C |
|
Set D |
||
|
Sample Name |
Products |
|
Sample Name |
Products |
|
C1 |
D0607 + D 0604 |
|
D1 |
D0610 + D 0604 |
|
C2 |
D0607 + D 0613 |
|
D2 |
D0610 + D 0613 |
|
C3 |
D0607 + D 0618 |
|
D3 |
D0610 + D 0618 |
|
C4 |
D0607 + D 0623 |
|
D4 |
D0610 + D 0623 |
Bottle Testing- Demulsifier-Second Round Results
|
Sample |
% H2O Drop Out |
% BS Drop Out |
Water Clarity |
Interface |
|
BLANK |
0 |
0 |
na |
na |
|
COMPETITOR A |
0.0 |
0 |
No noticeable water drop |
No noticeable water drop |
|
COMPETITOR B |
5.0 |
0 |
4 - Good H2O clarity, |
2 - Ragged, Large oil droplets in water |
|
A1 |
7.0 |
0 |
4 - Good H2O clarity, |
3 – Good, Small Oil droplets in water |
|
A2 |
5.0 |
0 |
4 - Good H2O clarity, |
4 - Good, Small oil droplets in water |
|
A3 |
9.0 |
0 |
3 - H2O slightly cloudy |
4 - Good, Small oil droplets in water |
|
A4 |
3.0 |
0 |
5 - Clear H2O clarity, |
4 - Good, Small oil droplets in water |
|
B1 |
9.5 |
0 |
4 - Good H2O clarity, |
3 - Finely dispersed oil at interface |
|
B2 |
7.5 |
0 |
3 - H2O slightly cloudy |
3- Finely dispersed oil at interface |
|
B3 |
8.0 |
0.25 |
3 -Good H2O clarity, |
4 - Good, Small oil droplets in water |
|
B4 |
5.0 |
0 |
3 - Good H2O clarity, |
3 - Finely dispersed oil at interface |
|
C1 |
0.0 |
0 |
na |
na |
|
C2 |
0.0 |
0 |
na |
na |
|
C3 |
0.0 |
0 |
na |
na |
|
C4 |
0.0 |
0 |
na |
na |
|
D1 |
7.5 |
0 |
4 - Good H2O clarity, |
4 - Good,No Noticeable oil, very slight |
|
D2 |
0.0 |
0 |
na |
na |
|
D3 |
0.0 |
0 |
na |
na |
|
D4 |
0.0 |
0 |
na |
na |
Bottle Test Conclusions
The results show that the four best performing Chemiphase samples are the A1, A3, B1 and B3 samples. All four of
these samples exceeded the results obtained at the stage two trials by either the Competitor A or Competitor B product. The samples also matched or exceeded the results gained by either the Competitor A or Competitor B product at the stage one trials.
Conclusions & Recommendations
As you can see the Chemiphase Oilfield Demulsifier products have shown better performance in the demulsifer bottle testing than the competitors products.
The centrifuge test shows water drop out when using the Chemiphase products , exceed the 0.4% limit set by the client. The amount of water dropped out using the Chemiphase products consistently out performs the competition and the clarity of water produced is of a much high quality than is produced when using non Chemiphase products.