In-situ combustion method for enhanced oil recovery is commonly used for
Show Hint
- gas condensate reservoirs
- light oil reservoirs
- brown oil reservoirs
- heavy oil reservoirs
The Correct Option is D
Solution and Explanation
It is a thermal EOR method where a portion of the reservoir oil is ignited; the combustion front moves through the formation, generating heat.
Step 2: Why for heavy oil?
Heavy oils are highly viscous; heating dramatically lowers viscosity and improves mobility and displacement efficiency. The generated flue gases also aid drive.
Step 3: Eliminate other options.
Gas condensate and light-oil reservoirs already have good mobility; thermal methods are unnecessary or inefficient compared to gas or miscible processes. “Brown oil” is not a distinct fluid type for which thermal EOR is preferred.
Conclusion: In-situ combustion is best suited to heavy oil reservoirs.
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Questions Asked in GATE PE exam
Identify the option that has the most appropriate sequence such that a coherent paragraph is formed:
Statement:
P. At once, without thinking much, people rushed towards the city in hordes with the sole aim of grabbing as much gold as they could.
Q. However, little did they realize about the impending hardships they would have to face on their way to the city: miles of mud, unfriendly forests, hungry beasts, and inimical local lords—all of which would reduce their chances of getting gold to almost zero.
R. All of them thought that easily they could lay their hands on gold and become wealthy overnight.
S. About a hundred years ago, the news that gold had been discovered in Kolar spread like wildfire and the whole State was in raptures.
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\[ \begin{aligned} N & = \text{Initial (original) oil in place, stb} \\ G & = \text{Initial volume of gas cap, scf} \\ m & = \text{Ratio of initial volume of gas cap to volume of oil initial in place, rb/rb} \\ S_{wi} & = \text{Initial water saturation} \\ S_{oi} & = \text{Initial oil saturation} \\ B_{oi} & = \text{Initial oil formation volume factor, rb/stb} \\ B_{gi} & = \text{Initial gas formation volume factor, rb/scf} \end{aligned} \]
The total pore volume (in rb) of the reservoir is:
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