Description
Pipelines carrying crude oil, especially those of small bore, not infrequently become at least partially blocked. Even if complete blockage is avoided, the loss of throughput due to flow resistance caused by the buildup of accretions on the walls of the pipeline can greatly degrade the maximum flow capacity of the line. These accretions usually result from the build-up of paraffin waxes and other high-melting point components of the crude stream (some of which can easily separate out, especially in cold weather) on the pipeline wall, together with scaling of the inner surface of the pipe due to corrosion.
Small-bore pipelines can best be treated while in normal flow mode - no shutdown is necessary, although there may be a slight advantage if a pipeline is already out of use. Smaller-bore lines such as those typically used for oilfield collection systems can also be treated in longer segments (e.g., between pumping stations) and when flowing oil.
Ideally, big-bore pipelines (e.g., 1 meter diameter) should be treated in segments of approximately 200 meters in length - in effect, as a horizontal, cylindrical tank, but this is usually difficult to arrange. Large-bore lines may need some post-treatment mechanical cleaning (which will now be much more effective due to loosened deposits), e.g., using a motorized mechanical "pig", but the OIL-XORB ERC treatment alone is usually sufficient.
Procedure
The OIL-XORB ERC concentrate must be used diluted 1:10 in water (e.g., 100 gallons of OIL-XORB ERC to 1000 gallons water) in a holding tank and then heated to 170-200° F (77-93° C). For this purpose, a mobile heater truck is recommended (readily available in the US). The line to be treated, if of large diameter, should be closed off in segments and treated as if it were a tank. It is important that the hot OIL-XORB ERC solution fill the entire segment being treated and that it be circulated as vigorously as possible to ensure maximum turbulence.
For smaller-bore pipelines and, in some cases, larger ones, it has proven possible to clean pipelines on-line (while they are flowing oil) by simply injecting OIL-XORB ERC at ambient or higher temperature (the higher the better) into the flow stream for a period, preferably at multiple points around the pipe. The mixture of oil and OIL-XORB ERC solution must then be pumped into one or more large holding tanks at the end of the pipeline (as would normally happen anyway) to allow good separation of the water solution of OIL-XORB ERC and debris (such as scale) from the pipe.
Disposal
The paraffin's stripped from the pipe walls are re-dissolved in the crude stream or, if no crude is present, can be skimmed off the cleaning solution in the holding tank. OIL-XORB ERC appears to reduce the viscosity of the paraffin's so that they are liquefied, which makes re-solution easier. Scale and other solid material falls to the bottom of the holding tank provided that flow in the line is sufficient to transport them that far. The supernatant oil is of pipeline quality (i.e., contains less than 1% water), separates sharply from the residual OIL-XORB ERC solution after a fairly short holding period and is easily pumped off, preferably into a storage tank. The OIL-XORB ERC-water bottom layer can be re-used or disposed of, either through dilution or disposal in waterways. It is fully degradable and is non-toxic.
Product Recovery
OIL-XORB ERC aggressively promotes the separation of the hydrocarbon phases from the cleaning solution, resulting in a hydrocarbon-free cleaning solution for recovery and recycling and a water-free hydrocarbon phase which, absent any other contamination (e.g., from non-OIL-XORB ERC cleaning systems) can be re-blended with the crude stream or used elsewhere. The amount of oil recovered is typically 1-20 bbl per 1,000 U.S. gallons of OIL-XORB ERC-water solution used.
Competing Products
There are no other products known to or tested by OIL-XORB ERC that offer the performance and ease of use of OIL-XORB ERC. Hydrocarbon-based systems, solvent-based systems and even those based on natural oils are often environmentally unfriendly and result in contamination of the recovered crude and paraffin's. Neither these systems nor any other water-based system known to OIL-XORB ERC offers the same combination of low cost, ease of use and environmental friendliness that is available with OIL-XORB ERC.
Product Costs
OIL-XORB ERC is at least $100/bbl less costly than any known (and less effective) competitor. In addition, most competing products must be used in undiluted or only slightly diluted form while OIL-XORB ERC is used at 1:10 dilution (slightly more concentrated solutions, but never more concentrated than 1:5, may be needed for removal of very severe deposits).
Other Benefits
OIL-XORB ERC not only prevents oil/water emulsion formation but also destabilizes any existing emulsions. It also leaves a film on cleaned metal surfaces that helps to prevent scale formation and can also be painted, if needed.