Phoenix Chemical Corp.
16541 Redmond Way # 212C
Redmond, WA 98052
Why Your Well Needs PARC400
The deposition of paraffin and asphaltene in oil wells are among the most common problems leading to the deterioration of oil and gas production; however, they are among the easiest to remedy with proper treatments. An increase in production of 10%, 30% or even 100% after proper treatment is not uncommon in wells having paraffin and asphaltene problems.
Some wells that have wax problems may also have a combination of other problems; thus paraffin treatments alone may not be sufficient to optimize production. Wells where paraffin problems are the primary reason for production deterioration have the best chance of production increase after treatments.
When increased production is possible, it is usually experienced after the removal of wax buildup that has been deposited in the formation (formation damage). The removal of those deposits precipitated in the formation restores permeability and again allows the free flow of petroleum. The removal of the deposits in the tubing, flow lines, storage tanks, etc. leads to increased efficiency, decreased operational cost and minimized down time.
There are several causes leading to the deposition of paraffin and asphaltene in the formation. Some of those causes occur naturally, others are induced by well specific production practices. Natural causes include streaming potential (due to the flow of the oil); and temperature drop at the face of the formation, due to the expansion of the fluids as they enter the well bore. Deposition induced by the production practices include temporary vacuum pumping (attempting to pump more than the well’s capacity), injection of cool fluids (chemicals, acid, etc.) some solvent treatments, and most hot oil treatments.
Any organic deposit (heavy hydrocarbon deposit) associated with production is often called paraffin or wax. While paraffin compounds are usually the major component in these deposits, they are frequently a mixture of paraffins and asphaltenes. Their deposition in the formation, tubing, flow lines and other production facilities leads to a decrease in production and an increase in operational problems.
Crude oil quality differs even between two wells producing in the same field from the same reservoir. Therefore, crude oil paraffin and asphaltene content and its impact on production is well specific. Furthermore, Paraffin deposits, in addition to containing asphaltenes, may contain resins, gums, salt crystals, scales, clays, silts, sand and water.
Paraffins are straight or branched chain non-polar alkanes of relatively high molecular weight. Their chains usually consist of 20 to 60 carbon atoms with a melting range of 36 - 102°C (98 - 215°F). Asphaltenes, on the other hand, are high molecular weight cyclic aromatic compounds which usually contain nitrogen, oxygen and/or sulfur in their molecular structure. Their melting range is higher than that of paraffins. Asphaltenes are usually negatively charged polar compounds.
In general, the lower the API gravity of the crude, the more asphaltene present, e.g., crude of 9 API gravity contains about 82% asphaltene, whereas a crude of 41 API gravity contains only about 3% asphaltene.
The presence of paraffin and asphaltene in the crude oil does not lead to problems in production or operations. It is their precipitation that leads to those problems. The precipitation and deposits of paraffins and asphaltenes are generally caused by a change in equilibrium conditions surrounding the produced petroleum, i.e., pressure, temperature, flow rates and/or electrostatic effects.
Deposition in the Formation
Streaming Potential, Cooling and Pressure Drop:
Treatment with Cool Fluid:
Hot Fluid Treatment:
Deposits in the Tubing and Production Lines
It is important to note that once a thin film of hydrocarbon deposit is formed on a surface, the rate of further deposit accumulation is drastically increased, thus the typical production drop curve associated with waxing off is observed.
As the well gets older, the well usually develops an increase in paraffin and asphaltene problems because of the following:
Unless the deposits are removed, the operator is often faced with a decrease in production, increase in pump problems, waxing off of the tubing and other production lines, and a possible total loss of production.
If you would like to receive additional information, please contact us.