We are told in line 47 that oil based mud is normally used for drilling deeper wells. Thus, if answer choice (C) were true, i.e. if shallow depth oil reserves have mostly been tapped, then only the deeper ones are left over. So, since the passage directly tells us that UBM is normally used for deeper wells, this leads us to predicting that the proportion of oil-well drilling using OBMs will increase in the future.
Hope that clears things up! Please let us know if you have any other questions.
mwilson1615July 23, 2019
I got this one right, but I was curious why (A) was incorrect? I was juggling between the two...
IrinaJuly 23, 2019
@mwilson,
(A) is incorrect because it requires us to assume that WBM and OBM mixtures are interchangeable, but the passage suggests that WBM is used for shallow wells and OBM for deep water drilling. If there are in fact certain properties of WBM/ OBM that make them suitable only for shallow/ deep wells respectively, then the cost of WBM ingredients is irrelevant because WBM/ OBM are not substitutes in the economic sense. Since we have insufficient information to make this determination, (A) is a weak answer choice compared to (C) that clearly establishes the correlation between OBM & deep-water drilling.
johnawhitevSeptember 30, 2021
Why are B & D wrong on this question? Additionally, what is the best strategy for making these deductions under timed pressure because I feel like the timer is what holds me back
RaviFebruary 5, 2022
B is wrong because even though this choice is dealing with a the deep offshore wells that companies have to use OBMs to drill, it doesn't tell us that these companies will have to drill at these deep wells more frequently, so it doesn't strengthen the prediction that more oBMs will be used in the future.
D doesn't work because it has no effect on the prediction that more OBMs will be used in the future. We don't have any reason to believe that developing more efficient ways of removing OBM residue from cuttings will affect how often OBMs will be used.
For this question, treat it like a strengthen question in LR. You're looking for something that, if true, will provide support for a prediction that the proportion of oil-well drilling using OBMs will increase in the future. Try doing some drilling in analytics with strengthen questions to help with these.
