Steam Injection Followed by Air Injection Air injection as a follow-up process has the potential to recover significant additional oil after steam injection. Application The following characteristics are beneficial to the application of steam injection: If the pipe is uninsulated, the term applies.
This "J-well" design acts as a vertical separator that helps distribute steam to the end of the wellbore, prevents steam condensate from inhibiting injection, and should retain gas and steam better in the reservoir during the production cycle.
Concurrently, CADP for the cycle will begin to increase as the daily production begins to pay for the injection costs.
Second, because of the time delay in oil response from the initiation of steam injection into a continuous steam injector in a steamflood project, CSS concentrated in the steamflood zone is often used to accelerate project response.
Concurrently, CADP for the cycle will begin to increase as the daily production begins to pay for the injection costs. Heated steam is injected into the upper well, where the build-up of pressure and heat melts the bitumen and causes it to flow downward to the second horizontal well, from which it is pumped to the surface.
Cumulative Average Daily Profit Method Because process optimization is ultimately an economic decision, a resteaming decision can be based on the Rivero and Heintz  cumulative average daily profit CADP method.
Environmental concerns present a considerable obstacle to steam injection operations. Optimal performance of SAGD requires that the steam chamber be kept well drained so that liquid does not accumulate over the producer, without producing steam vapour.
Surface and wellbore heat losses can be partially controlled but reservoir conditions cannot, and they are the most critical in determining project feasibility. Cases in excess of 20 cycles have been reported Herbeck et al.
SAGD is best suited to bitumen and oils with low mobility, which is essential to the formation of a steam chamber.
Formation Heat Efficiency The efficiency of formation heating by steam injection depends on the amount of heat lost from the surface equipment, the injection wellbore, and to adjacent formations as the steam is transported from the generator out into the reservoir. By steaming wells in a sequential manner from downdip to updip as shown in Fig.
It is common practice to cover insulation with a thin sheath of bright aluminum, mainly for protection from weather and from mechanical abuse. A chromosome representation, crossover and mutation operators generating only feasible solutions and thus avoiding the use of any repair mechanism are discussed.
Once the third stage is completed the production cycle is repeated a number of times till production becomes uneconomical. Generally, with an increase in temperature, relative permeability to oil increases, while that to water decreases.
A lack of understanding of the process dynamics and poor reservoir characterization are largely to blame. This is also sometimes referred to as huff and puff technique. The total weighed tardiness is used as the goal of the optimization process. It is important to be aware, however, that lower reservoir pressures increase the challenges of lifting the oil to the surface.
Soaking stage, allowing the separation of oil from other ingredients, allowing reservoir pressure to build. Because many CSS candidates have only gravity forces and initial viscosity is high, there is no significant primary production.
After looking into the specifics it is going to need to be approximately mw. Sand thicknesses of at least 30 ft to 50 ft are necessary to limit formation heat losses in continuous steam injection projects. Very little is published on optimizing CSS. Because bitumen defined as being heavier than 10oAPI is nearly immobile at reservoir temperature, steam cannot be injected at significant rates without fracturing the reservoir.
It is widely used for petroleum extraction from oil sands and reservoirs with very heavy crudes, in California, Alberta Canada as well as other places. Note that solvent-based processes alone for heavy oil recovery are generally slower than thermal processes. A positive downward pressure gradient was effectively used to mitigate water coning.
Note that for every system there is an optimum insulation thickness. This reservoir see Figure 10 is a 13m-thick sandstone located on the Alberta-Saskatchewan border. Adding more insulation above this optimum will not result in more heat savings.
For horizontal reservoirs, where the producing mechanism is solution gas drive, reservoir energy is quickly depleted, limiting the number of cycles. The following are useful in most cases, but the reader should refer to appropriate   texts for more complicated systems.
Articles References Ault, J. Steam Distillation and Solvent Drive In the displacement of volatile oils by steam, lighter fractions of the oil may be vaporized.
Thermal resistance to heat loss for that system is In either case, heated oil drains from around growing steam chambers, driven by gravity to lower horizontal wells. Cyclic steam stimulation (CSS) is one of the principal enhanced-oil-recovery methods for heavy oil.
CSS was performed in some of the wells of a heavy-oil field.
SPE Distinguished Lecturer Program Primary funding is provided by The SPE Foundation through member donations and a contribution from Offshore Europe Cyclic Steam Stimulation (CSS) CSS • Single well operation • Injection/production cycle: – Steam injection – shut-in (soak).
Vista’s client constructed a Cyclic Steam Stimulation pilot project at an existing licensed cold production heavy oil field in northwest Alberta. The pilot facility is designed to produce a maximum m3/day (1, barrels per day) of emulsion.
Cyclic steam injection is used extensively in heavy-oil reservoirs, tar sands, and in some cases to improve injectivity prior to steamflood or in situ combustion operations.
Cyclic steam injection is also called steam soak or the huff `n puff (slang) method. Some have compared the process of Cyclic Steam Stimulation (CSS) to a chemical-free version of fracking.
Unlike the more common well stimulation practice called steam flooding, cyclic steaming injects steam at high pressure specifically to break up relatively shallow, diatomaceous soil.
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