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autoRTA: Wellbore Model

Introduction

In autoRTA, the user has a number of options for using various pressure types, and calculations

There are two main options which are:

  1. Flow Pressure Type (or source). Refer to Types of Pressures for additional detail

  2. Wellbore Model


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Flow Pressure Type:

Most pressure sources are imported with the production data via either Import Wells option, or the AFADatabase Integration Capabilities which may include Tubing, Casing, PDHG, PIP, and more. However, a user can override these imported values and use single custom value for particular dataset. In the plots shown below, the user has chosen a manual input “Constant Pressure“ of 200 psia.

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Wellbore Model

Currently, there are two types of wellbore available:

  1. No Model - Assumes what ever pressure type or source is selected, this pressure is representative of the wellbore pressure at sandface.

  2. Beggs & Brill Multiphase Wellbore Flow - A empirical model for multiphase flow in a closed conduit. For details of this model and its options are shown below:

It is important to note that the “Well Angle“ is measured from the horizontal axis as demonstrated in the image below:

The flow model, whether Beggs & Brill or similar models, generally take the following parameters

  1. Tubing Diameter: The Internal Diameter (ID) of the flow path

  2. Tubing Roughness ; The unevenness of the surface of the tubing.

  3. Tubing Depth: The length of the tubing, or a point within the wellbore to which a surface pressure to be converted. This can also be any distance including the depth from a pump intake pressure to MPP or similar.

  4. Wellhead Temperature: Average or typical temperature at well.

  5. Well Angle, the angle of the wellbore relative to the horizontal (see below)

RTA_Wellbore.png