Author: haroonkhan

The steam-drive process is much like a conventional waterflood. Once a pattern arrangement is established, steam is injected into several injection wells while the oil is produced from other wells. This is different from the steam stimulation process, whereby the oil is produced from the same well into which the steam is injected. As the…

The steam-cycling, or stimulation, process was discovered by accident in the Mene Grande Tar Sands, Venezuela, in 1959. During a steam-injection trial, it was decided to relieve the pressure from the injection well by backflowing the well. When this was done, a very high oil production rate was observed. Since this discovery, many fields have…

Primary and secondary production from reservoirs containing heavy, low-gravity crude oils is usually a very small fraction of the initial oil in place. This is due to the fact that these types of oils are very thick and viscous and, as a result, do not migrate readily to producing wells. Figure 11.10 shows a typical relationship between…

The main technical problems associated with chemical processes include the following: (1) screening of chemicals to optimize the microscopic displacement efficiency, (2) contacting the oil in the reservoir, and (3) maintaining good mobility in order to lessen the effects of viscous fingering. The requirements for the screening of chemicals vary with the type of process.…

Microbial enhanced oil recovery (MEOR) flooding involves the injection of microorganisms that react with reservoir fluids to assist in the production of residual oil. The US National Institute for Petroleum and Energy Research (NIPER) maintains a database of field projects that have used microbial technology. There has been significant research conducted on MEOR, but few…

When an alkaline solution is mixed with certain crude oils, surfactant molecules are formed. When the formation of surfactant molecules occurs in situ, the interfacial tension between the brine and oil phases could be reduced. The reduction of interfacial tension causes the microscopic displacement efficiency to increase, thereby increasing oil recovery. Alkaline substances that have…

When an alkaline solution is mixed with certain crude oils, surfactant molecules are formed. When the formation of surfactant molecules occurs in situ, the interfacial tension between the brine and oil phases could be reduced. The reduction of interfacial tension causes the microscopic displacement efficiency to increase, thereby increasing oil recovery. Alkaline substances that have…

The basic micellar-polymer process uses a surfactant to lower the interfacial tension between the injected fluid and the reservoir oil. A surfactant is a surface-active agent that contains a hydrophobic (“dislikes” water) part to the molecule and a hydrophilic (“likes” water) part. The surfactant migrates to the interface between the oil and water phases and…

The addition of large molecular weight molecules called polymers to an injected water can often increase the effectiveness of a conventional waterflood. Polymers are usually added to the water in concentrations ranging from 250 to 2000 parts per million (ppm). A polymer solution is more viscous than brine without polymer. In a flooding application, the…

Chemical flooding processes involve the addition of one or more chemical compounds to an injected fluid either to reduce the interfacial tension between the reservoir oil and injected fluid or to improve the sweep efficiency of the injected fluid by making it more viscous, thereby improving the mobility ratio. Both mechanisms are designed to increase…