Question1)a) Name and explain the rock properties and reservoir characteristics which would be essential to estimate original hydrocarbons in place. Explain the recovery factor of oil and gas.
b) How is reservoir heterogeneity classified on different geological representative scales?
Question 2)a) What is reservoir characterization? What basic information is needed to characterize the reservoir? How is it recognized using seismic and well data?
b) What is deterministic, random and stochastic or mixed reservoir? Describe with the help of neat diagram, a multilayered reservoir which shows discrete/sharp changes and gradual changes in a sand-shale sequence.
Question 3)a) A Plot of annual production against time for the asset indicates which production will continue for 17 more years before reaching the economic limit of 1,750 bbl/year. The line of extrapolation passes through 15,000 bbl for the last year of available data. Though production data shows that actual production for that year was 14,300 bbl and that some downtime had been experienced.
Compute the recovery (current reserves), that can be expected over the next 17 years before production reaches the economic limit of 1,750 bbl / year assuming (i) h = 0 and (ii) h = 0.5.
What would be the value of the reservoir if the oil price is $ 40/barrel throughout the tenure of project?
b) Write a note on reservoir drive mechanism.
Question 4)a) How do three decline curve methods differ from each other?
b) Give the overview of different material balance methods to compute reserves
Following are the assumptions for the preparation of spreadsheet and further calculations.
i) Oil price is $ 50 per barrel and will remain constant.
ii) Royalty is 10% of annual revenue/ annual production.
iii) Time value of money is 10%.
iv) Profit petroleum is shared between government and contractor at 50 : 50 proportions respectively.
v) Income tax is 30%.
b) Write detail notes on the following:
i) Function of horizontal wells in increasing reservoir recovery.
ii) Integration of seismic and well data using Geostatistics.
iii) 3 D reservoir modelling.
iv) Steps involved in the procedure for determining the hydraulic flow units using Geostatistics and conventional methods.