i think the interviw was of intermediate level not so easy...here are answer of question...hope u will improve my answers.
(1)What is natural gas?
Natural gas is a combustible mixture of hydrocarbon gases
(2)Main constituents of natural gas when it is produced from a well?
While natural gas is formed primarily of methane, it can also include ethane, propane, butane and pentane.In its purest form, such as the natural gas that is delivered to our home, it is almost pure methane. The distinctive “rotten egg” smell that we often associate with natural gas is actually an odorant called mercaptan that is added to the gas before it is delivered to the end-user. Mercaptan aids in detecting any leaks.
(3)Estimated gas reserves of pakistan?
Pakistan holds an estimated 33 trillion cubic feet (tcf) of tight-gas reserves.
(4)Is every drilled well able to produce gas?
not sure...but i think the scientist whatever they are drill well only when they are sure about the gas at that place.
(5)Number of consumers of sngpl?
more than 3.4 million consumers