Asphasol

Asphasol is a cost-effective, high-performance additive effective in a wide range of water-based systems for both low and high temperature wells. Asphasol is renowned as an excellent shale stabilizer.

Mixing guidlines

If excessive product losses are being experienced over the shakers, it is recommended to employ coarser screen sizes during initial stages of product addition, and then switching over to finer sizes. It is not uncommon to experience a 10 to 20% loss over shakers during initial stages of additions, and in some areas may be considered normal and within acceptable limits. Asphasol solubility is much dependent upon temperature, and circulation time. Asphasol will more rapidly mix into the mud system as the fluid temperature increases. If the mud is very cool, it may be best to hold off additions until it has a chance to warm up. An amount of Dilution may also be required during initial additions. Continual additions of Asphasol will be needed to maintain a sufficient concentration in the system if losses occur while drilling. Asphasol is consumed while depositing on drilled solids and on the well bore. It is advisable to add 50% more, one day following the initial treatment, to ensure adequate concentration. Use a conventional hopper when chlorides do not exceed 60,000 ppm. When adding to high salinity systems, pre-wetting the Asphasol with fresh water by adding through a chemical barrel or pre-mix tank will improve results.

Pre-mixing

Asphalt materials (including Asphasol Additive), may have some preliminary losses over the shaker. Precautionary actions to eliminate or reduce this possibility may be necessary. Pre-mixing is recommended even if the product is not running over the shakers, as the thorough solubility before mixing with whole mud, leads to better hole stability. If Asphasol Additive cannot be added directly to the system through the hopper, it can be added to the system using a chemical barrel or pre-mix arrangement. Add 40-50 ppb of Asphasol Additive to the base mud and then bleed it into the active system. Agitation, stirring or circulation may possibly be required in the pre-mix tank or chemical barrel to prevent excessive settling. Pre-mixing in freshwater is recommended as the bestmethod, even when adding to an oil base mud system. Make up salt such as calcium chloride can be added to the pre mix, but this is usually not necessary asthe amount of fresh water added to the system via concentrated pre-mix solutions will be negligible.

Pre-mixing in freshwater

Mixing in freshwater might be the simplest and cheapest solution. Mix 40-50 ppb of Asphasol Additive in a slug pit of freshwater. There could be

PRE-MIXING IN HIGH SALT MUDS RIG SITE MIXING

AsphasolAdditive can usually be mixed into high salt (60,000 ppm chlorides and up), high density drilling muds without problems if some extra steps are followed. If
enough time is available, both products may be added gradually over several days to an existing system allowing both time and temperature and shearing at the bit to disperse the product. This slow addition of the product reduces losses at the shale shaker which would be expected under these conditions. However, if hole conditions require large amounts of Asphasol Additive be added quickly, it is best to prewet
the Asphasol Additive with freshwater in a separate mixing tank. In fresh water
large amounts of either product up to 200 ppb may be mixed to create a slurry that may be added direct to the mud system without much loss at the shale shaker.