Types of Pressures

Introduction

In AFA, there is the ability to use different pressure sources within various models. The three (3) most common are:

Casing Pressure: Casing pressure is the pressure between the casing and tubing at wellhead (I.e., annulus). If the well is naturally flowing up tubing, the casing pressure may provide a more stable estimate/calculation of Bottomhole Pressure if the annulus is open to the perforations (one can exclude frictional losses). If there is pumps or other equipment in the tubing, it may be absolute necessary to use casing pressure unless there are PDHG, Pump Intake Pressures, or other downhole source.
Tubing Pressure: Tubing pressure is measured as the wellhead,. If the well is naturally flowing up the tubing, one can use tubing pressure to calculate BHP, but must account for both hydrostatic and frictional losses etc.
Bottomhole Pressure (BHP): Often used to describe pressure at mid-point of perforations (MPP) or some downhole reference point.
Pump Intake Pressures (PIP): A pressure sensor on the inlet of pump (not the outlet)
Permanent Downhole Gauges (PDHG): Permanent downhole pressure and temperature gauges for real-time data acquisition and monitoring in oil and gas wells. Permanently located downhole near the perforations or the zone of interest.

In many of the AFA modules, the user can select which source pressure they might choose to use in modules as: