(Wireline 16) Perforating and stale primer (detonating) cord. Rated as a FGE.

Schlumberger was starting to build up their perforating and well completion services in California. It had always been there but not very big. I started learning and doing more of this type work. I have previously mentioned the exam required to be be rated as a Schlumberger Field General Engineer (FGE). To be so rated an engineer had to be qualified to run every wireline service offered by Schlumberger. I was anxious to become proficient in well completion services and to qualify.

I had perforated several gas wells in an area and knew how they should act. One day I ran a capsule shape charge gun into a well through a blow out preventer. Within a few minutes of perforating the gas zone would produce and put several hundred pounds pressure on the well head and we would have to come out of the well using the blow out preventer. On this particular well, after we fired, there was no pressure, no gas. We knew that we had not made any perforations. However the gun had fired.  Maybe the primer cord was stale? We ordered fresh cord from the shop and made up a new gun. After using it we had normal pressure. Evidently the cord was strong enough to make the charges explode but did not hit the charges strong enough to form a strong jet? Primer cord has to be stored in a cool dry place. Its shelf life is five years. From then on I paid attention to the date on the cord.

It was job (for me anyhow) to become rated as a Field General Engineer. I had to pass an all day oral exam in California, then fly to Houston and repeat the exam before a three man board. I passed. At one time long ago I knew a little bit about oilfield wireline services.