As generally known, subsurface pressure can be implied using both wireline logs and drilling events. However, there may a case where events do not indicate the same pressure. Data from four vertical wells located in South Sumatra Basin, Indonesia, were analyzed as study. Two wells, Wells A D, encountered high overpressured zones, confirmed by data. The two others, B C, only low inferred relativ...

Abstract Wellbore instability causes main concerns in the oil and gas industry due to personnel safety overall expenditure. Several signs such as wellbore spalling, rate of penetration reduction, pipes sticking, well unnatural wash out, collapsing, induce fracture could indicate during drilling. A balance between stress concentration near rock strength is primary condition for a stability Thus,...

Underbalanced drilling as multiphase flow is done in oil drilling operation in low pressure reservoir or highly depleted mature reservoir. Correct determination of the pressure loss of three phase fluids in drilling annulus is essential in determination of hydraulic horsepower requirements during drilling operations. In this paper the pressure loss of solid-gas-liquid three-phase fluids flow in...

underbalanced drilling as multiphase flow is done in oil drilling operation in low pressure reservoir or highly depleted mature reservoir. correct determination of the pressure loss of three phase fluids in drilling annulus is essential in determination of hydraulic horsepower requirements during drilling operations. in this paper the pressure loss of solid-gas-liquid three-phase fluids flow in...

It is not possible to directly measure the total mass of gas and liquid in the annulus and geological properties of the reservoir during petroleum exploration and production drilling. Therefore, these parameters and states must be estimated by online estimators with proper measurements. This paper describes a nonlinear Moving Horizon Observer to estimate the annular mass of gas and liquid, and ...