Design Tools

PC-PUMP® contains a System Configuration module that allows users to enter wellbore geometry information, select casing and tubing sizes, build a rod string from various rod manufacturers and types, and finally select a pump to evaluate downhole. Alternatively, a downhole drive system can be specified and analyzed.

In Analysis Inputs, you specify the fluid properties and operating conditions appropriate for the well you are analyzing, and then you click on the calculate button.

PC-PUMP® has many user-friendly features that minimize design time, such as the ability to run equipment or batch comparisons. In addition, PC-PUMP® has default settings that can be specified by the user for easy facilitation of multiple well designs.

Wellbore Geometry

The wellbore geometry window enables the user to enter an existing wellbore profile or create one using the well design mode. Possible wellbore input methods include importing a text file or copying information from an excel file.

System Configuration

PC-PUMP® contains a System Configuration module that allows users to enter wellbore geometry information, select casing and tubing sizes, build a rod string from various rod manufacturers and types, and finally select a pump to evaluate downhole. Alternatively, a downhole drive system can be specified and analyzed. If desired, the user can specify different possible equipment configurations for comparison. More detailed descriptions of each section is provided below.

Pump Selection

The pump selection window allows the user to select one or more pumps for analysis from an extensive database containing almost 2000 pump models. Features of the pump selection window include:

 

Bench Test Module Enter bench test results
Custom Pump Module Enter a new pump
Variable Efficiency Module Calculate the volumetric efficiency as a function of differential pressure and pump speed
Stator Swell Module Estimate the amount of rotor-stator interference and additional require torque based on an elastomer swell test.

Tubular Selection

The tubular selection window allows for the selection of casing, tubing, tail joints and diluent injection. For downhole drive systems a shroud can be selected in place of a tail joint. PC-PUMP® has the ability to notify the user when the selected pump and tubing will not fit in the selected casing. Tapered tubing and casing strings can also be entered.

Rod String Selection

The rod string selection window enables the user to build almost any type of rod string using continuous, standard or hollow rods. Couplings and rod guides can be added, where the number of rod guides per rod can be specified or selected by the program program based on a maximum tubing/rod contact force. A powerful aspect of the rod string window is the ability for the user to build a rod string with different characteristics at different depths. For example, a portion of the rod string could be composed of smaller diameter continuous rod while the remaining portion is composed of larger diameter standard rods with rod guides.

Surface Drive Equipment Selection

In surface drive mode, the selection of drive equipment is optional. The surface equipment consists of a drivehead, belts, hydraulics and a prime mover. Driveheads, hydraulic pumps and hydraulic motors are selected from a database of vendor equipment.

Downhole Drive Equipment Selection

In downhole drive mode, the drive equipment must be specified, as it can have a significant impact on the flow between the perforations and the pump intake. Downhole drive equipment consists of three parts: the motor, the “drive assembly”, which PC-PUMP® defines to be all the equipment between the motor and the pump (which normally includes a seal, gear box and flex-shaft), and a power cable. PC-PUMP® will ensure that the cable will fit between the tubing collars and the casing. It will also ensure that the motor and drive assembly fit inside the casing or shroud. Custom downhole drive equipment can alse be entered.

Fluid Properties

The fluid can be specified to be single-phase (no gas) or multi-phase (solution gas and/or free gas is present). Fluid properties for single-phase fluid can be entered by specifying the actual density, or by specifying the fluid composition—allowing the program to calculate the density. Fluid properties for multi-phase fluid takes into consideration the location of the pump intake (or tail joint or shroud intake if applicable) with respect to the perforations to determine the amount of free gas present in the pump.

An advanced viscosity option is availble for single-phase fluid to account for changes in viscosity due to temperature, shear rate, and/or water fraction. For multi-phase fluids the advanced viscosity option allows the dead oil viscosity to be specified as a function of temperature, which will improve accuracy of the results, especially for heavy oil.

Operating Conditions

The operating conditions panel allows the user to specify basic downhole conditions and how the system will be run. The panel includes a series of flow rate parameters (fluid rate and pump speed), downhole pressure parameters (fluid level, submergence, bottomhole pressure and motor frequency (downhole drive mode only)) and IPR (Inflow Performance Relationships) data.

Calculation Types

Four calculation options give the user the ability to perform different calculations depending on the information they are looking for. These options can save time and provide insight into system performance that would not have been possible otherwise.

Standard Calculation

A standard calculation runs one calculation case, using one equipment case and one pump at one set of operating conditions.

Pump Comparison

A pump comparison runs a number of cases, all using the currently selected equipment case, but with different pumps.

Equipment Comparison

An equipment comparison is similar to the pump comparison, except that one pump is used and different equipment cases are run.

Batch Comparison

A batch comparison runs one equipment case and one pump through a range of operating conditions or fluid properties. Operating conditions or fluid properties that can be varied over a specified range include:

 

Fluid rate Fluid level Pump speed
Bottom hole pressure Submergence Water Cut
Density Motor frequency Viscosity


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