Natural gas liquids: What is meant by “casing-head gasoline” obtained in oil and gas operations?
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APropane collected at the wellhead
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BButane condensed from associated gas
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CNatural gas as produced from the reservoir
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DGasoline condensed from wet natural gas by compression at the wellhead
Answer
Correct Answer: Gasoline condensed from wet natural gas by compression at the wellhead
Explanation
Introduction / Context:In petroleum production, associated gas emerging with crude oil often contains heavier hydrocarbons. When compressed and cooled, part of this mixture may condense into a liquid hydrocarbon stream historically termed casing-head gasoline or natural gasoline.
Given Data / Assumptions:
- Wet natural gas contains C3+ components that can condense under modest compression and cooling.
- Field equipment can separate a liquid hydrocarbon phase for shipment or stabilization.
- This condensed liquid resembles a light naphtha/gasoline-range stream.
Concept / Approach:
By raising pressure and sometimes lowering temperature, the heavier ends of associated gas condense into a liquid. This is not the same as pipeline-quality dry gas. The condensed liquid is termed casing-head gasoline and can be stabilized and blended into refinery naphtha or gasoline pools after appropriate treatment.
Step-by-Step Solution:
Identify the source: wet natural gas from the well casing.Apply compression/condensation: heavy hydrocarbons form a liquid phase.Recognize the product name: casing-head gasoline = natural gasoline condensed from wet gas.Verification / Alternative check:
Field practices include lease condensate and natural gasoline recovery in stabilization units and field separators. These streams are distinct from pure propane or butane products.
Why Other Options Are Wrong:
Propane/Butane alone: Pure C3 or C4 streams are specific LPG cuts, not the multicomponent liquid called casing-head gasoline. Natural gas: Refers to the gaseous phase, not the condensed liquid.
Common Pitfalls:
Equating LPG components with natural gasoline; ignoring the mixed C5+ character of the condensed liquid.
Final Answer:
Gasoline condensed from wet natural gas by compression at the wellhead