RES SIM CH2 Flashcards
Difference between component and phase
Component - CH4, C2H6 (GAS)
C3H8, C5 (OIL)
H20 (WATER)
Phase - rock, gas, oil, water
Darcy Law Assumptions
Steady State Laminer flow Homogenous rock 100% saturated rock no reaction between rock and fluid - inert
Conditions for Material Balance
- Adequate data collection (P/PVT/PROD)
2. Reservoir is ‘tank like’. …. As system pressure falls, system equilibriates.
Process for Material Balance. What is it used for?
- STOIIP
- Water Influx
- Predicting mean reservoir pressure
MB defines input and is excellent at H.M. production performance but shit at predictions, - where numerical modelling excels.
Buckley Leverret Theory
For: Geology and flow physics simplified saturation tacking provides qualitative understasnding breakthrough time producation efficiency after breakthrough full simulation required B-L used in streamline methods Gives exact solution 1 phase
What are the advantages of Material Balance models
Simple and addresses average field pressure for o/w/g production and water influx from given initial quantities and initial pressure.
When would engineer use material balance approach?
Due to its implicity one would always apply single material balance to assess field performance - to see if DP decline tallies with estimated field size, sources of influx and production.
When would an engineer use reservoir simulation approach?
When complex development strategy requiring spatial information is essential e.g. well placement, shale effects, gravity segregation…
Given all the problems and inaccuracies, which are known to exist in the application of reservoir simulation, why do engineers still use it?
Because it is the only tool we have to tackle complex reservoir development/flow problems, which extend material balance. It’s better than doinng material balance alone!
What is disadvantage of Material Balance model?
Cannot address why pressures in two sections of the reservoir are different as a single average pressure is a core assumption.
