FloWell were invited to clear a 27-mile subsea Pipeline in the Gulf of Mexico for a major American operator, which was connected to a floating platform by a flexible catenary.
This pipeline had been gradually building up over a 7-year period culminating with very aggressive Wax build up over the past year! Various efforts over the years had failed to prevent Wax Build up, but had succeeded in slowing the process.
A Drag Reducer (DRA) had been in use for the past year, which offered relief, but NOT a cure! Flow rate had reduced to less than 90 BOPH in the previous 6 months! Naturally, the platform operator had grown increasingly concerned, having tried other options to clear this pipeline, there was the great risk that it was on course for a potential blockage.
In their desperation, they invited the FloWell solution to be tried. Having read about the success in the clearing of a small pipeline in the Ukraine, together with a successful trial in the Gulf of Thailand – it was a gamble for the client to use a new product, still finding its way in the notoriously difficult business to penetrate, the Oil & Gas Industry!
This pipeline was unable to be pigged since first operation 7 years ago – however, the paraffin wax precipitation only began to be a major problem beginning the previous year with rapid buildup over the previous few months.
During the first week of injecting the FloWell solution there was no visible improvement. After thorough checking of the installation it was discovered that DRA was still being injected into the oil stream. It was requested to be stopped, which was done after much resistance and then the oil-flow decline STOPPED almost immediately.
It became a major success! 100 days losses were returned in 10 days, then by the end of the first two weeks, the flow increased from 90 BOPH to 145 BOPH, a staggering increase in such a short time.
This massive increase was due to the clearing of a major bottleneck in the flexible catenary connecting the platform to the sub-sea pipeline. Once this was cleared the major task of cleaning of the pipeline began.
These results were brought about by a dosage rate of no more than 250 PPM. The flow recovery of the pipeline at this dose rate was a steady two barrels of oil extra production per hour. This led to a steady increase in the bore size and capacity of the pipeline by removing the precipitation, by returning the paraffin precipitation that had built up in the pipeline. The increase in production covered the cost of the FloWell injection by a huge margin.
This will take a long time to totally clear, after all we were up against 7 years of buildup, it is a long pipeline which travels in an uphill direction, along with many small peaks and troughs along the way.
About a month into the project it was decided to see if it was possible to accelerate the recovery by increasing the dosage rate.
The graph shows perfectly what happened. All of a sudden, the flowrate started going back down.
Initially it was thought that there may have been something wrong with the FloWell solution and so the dosage rate was increased the again. The flowrate went down even further.
It was eventually discovered that FloWell was releasing so much solids, it was displacing the oil in the pipeline, the viscosity had gone down so much, it could not remove the released solids.
It was decided to discontinue temporarily the FloWell injection and all of a sudden, the flowrate went back up.
Within 24 hours the flowrate had returned to the previous best and even without FloWell, it maintained that flowrate.
The dosage rate was readjusted to the original 250 PPM application rate and the previous gradual rise continued.
A further, and even more amazing discovery was made when it became necessary to shut-in for urgent maintenance work.
On restart previously it often took up to a week to return to original flow because the cooling oil in the pipeline increased in viscosity to alarming levels.
To the astonishment of the operators, when the pumps were turned back on after 36-48hrs following the maintenance work, the previous flow rate returned IMMEDIATELY!
This had NEVER happened before! It proved that not only had FloWell eliminated paraffin wax precipitation but in reduced temperature conditions it maintained pumpable viscosity conditions. This proved to be a regular occurrence, after other shut-in events, over the following weeks!