Overbalance with Preexisting Fracs
In safety training, especially well control, can there be too much of a good thing? For the constant bottom hole well control method there is when weighting up kill a kicking well.
Eagle Ford Shale
The Eagle Ford is a shale and as such naturally has very low permeability and would not be expected to flow without stimulation. As the area matures and becomes developed the likelihood of drilling into preexisting high permeability fracs the likelihood and ability to induce flow will greatly increase. Conversations with drillers in the Eagle Ford seems to confirm that ability for new drill Eagle Ford wells to kick. Conversely, there they are also reporting that the frac mud weight and kill mud weight seem to be converging on newer wells.
Drilling Into Frac
As the Eagle Ford shale matures and develops we believe that due to the increasing density of propped fractures the trend of decreasing frac strength and increasing kick size will continue. In addition, we see that poor kick response, such as shutting in for too long on a gas kick as well as pressuring up too hard on the wellbore will induce increasingly larger fluid loss.
Keeping Eagle Ford shale wells from kicking in the future will require crews to be properly trained to balance wells. By constraining their circulating mud weights to a margin of safety based on the kill method and sticking to it this can prevent undue fluid losses and further kicks.