Laboratory Study of the Behavior of Conventional Intermittent Gas-Lift

The intermittent gas-lift (IGL) methods still remain a practical recourse for the extended production of petroleum wells in the on-shore fields of Brazil. The IGLs are a natural candidate to substitute the continuous gas-lift (CGL) method at a late stage of reservoir depletion; as so the IGLs require modest adaptation to the CGL installation. The IGLs also display operational and economical characteristics that make it a viable artificial lift method for many low producing wells. In such cases, it becomes advantageous to properly design the system and to optimize it. A laboratory apparatus was designed and built to study the operation of the conventional IGL, such as the concurrency of cycle stages, as presented by Carvalho (2004), the fallback for different operating conditions and the stability of cycles due to motor valve timing and adjustment of the gas-lift valve. The results of the tests performed by changing the operating variables of the IGL are presented here. These tests results show the types of dynamical behavior predicted by numerical simulations; therefore they will be useful in tuning the simulation models that will be applied to the large scale systems of petroleum fields.