[How to Read an EIA Crude Inventory Report]
Inventory [Build/Draw] per day = Supply [S] - Demand [D]
= [Production + Imports + Adjustment + SPR Draw] - [Refinery Input + Exports]
Use the above formula to arrive at the Total Build/Draw per day and then Multiply by 7 for the Weekly Inventory.
In the example above which is an inventory report for 22 May 2019, the calculation is as follows
[Production+Imports+Adjustment+SPR Draw] - [Refinery Input+Exports]
[12200+6943+872+162] - [16578+2922] = 677 per day
For weekly data, multiply by 7 days. 677*7 = 4739 per week
Since the data is in thousand barrels per day, converting into millions, it is 4.74 million build for the week
Very Simple. Hope it helps.