Backward Multiple-contact Test
- A laboratory test to determine the phase envelope between oil and enriched gas. The test is conducted by equilibrating an oil sample several times with fresh samples of gas. Intermediate components are stripped from the gas by multiple contacts with the oil. The test also indicates how many contacts are required before the oil with added intermediate components becomes miscible with the gas. The molar ratios at each contact step are typically designed using PVT simulation software that incorporates the fluid composition from the previous contact.