Sentence:  Prepayments of drilling expenses are deductible by tax-shelter investors only if the well is “<WSD>spudded</WSD>” within 90 days after the close of the taxable year in which the prepayment was made, and the deduction is limited to the original amount of the investment. 
Meaning of the word marked with <WSD> tags:  To begin drilling an oil well; to drill by moving the drill bit and shaft up and down, or by raising and dropping a bit.