Hammerlindl Method for Gas in Place Calculation using Excel

The Hammerlindl method is used to estimate the original gas in place (OGIP) of abnormally pressured gas reservoirs. The method was developed by Hammerlindl and involves plotting the cumulative gas production against the pressure depletion. The slope of the straight line obtained from the plot is used to estimate the OGIP. The method is based on the assumption that the reservoir pressure is proportional to the gas saturation pressure.

Basic Theory

The Hammerlindl method is based on the principle of material balance. It assumes that the reservoir behaves as a single-phase system and considers the gas expansion and compression in the reservoir…

The formula for gas in place (GIP) using the Hammerlindl method is given by:

$GIP = \frac{7758 \cdot h \cdot \phi \cdot c \cdot (p_{i} - p_{wf})}{B_{gi}}$

Procedures

Input Data: Collect reservoir data including net pay thickness ( $h$ ), porosity ( $\phi$ ), formation volume factor ratio ( $c$ ), initial reservoir pressure ( $p_{i}$ ), wellbore flowing pressure ( $p_{wf}$ ), and initial gas formation volume factor ( $B_{gi}$ ).
Formula Application: Apply the Hammerlindl formula to calculate gas in place ( $GIP$ ).
Excel Implementation:
- Create an Excel table with columns for each input parameter and the formula for $GIP$ .
- Input the collected data into the corresponding columns.
- Use Excel formulas to calculate $GIP$ based on the Hammerlindl method.
Scenario Example:
- Let’s consider a reservoir with the following data:
  - Net pay thickness ( $h$ ): 50 feet
  - Porosity ( $\phi$ ): 0.20
  - Formation volume factor ratio ( $c$ ): 1.5
  - Initial reservoir pressure ( $p_{i}$ ): 3000 psia
  - Wellbore flowing pressure ( $p_{wf}$ ): 500 psia
  - Initial gas formation volume factor ( $B_{gi}$ ): 0.005 reservoir cubic feet per standard cubic foot.

Excel Implementation

Parameter	Value
Net Pay Thickness ( $h$ )	50
Porosity ( $\phi$ )	0.20
Formation Volume Factor Ratio ( $c$ )	1.5
Initial Reservoir Pressure ( $p_{i}$ )	3000
Wellbore Flowing Pressure ( $p_{wf}$ )	500
Initial Gas Formation Volume Factor ( $B_{gi}$ )	0.005

$GIP = \frac{7758 \cdot 50 \cdot 0.20 \cdot 1.5 \cdot (3000 - 500)}{0.005}$

$GIP = 465,480,000 \, \text{scf}$

MATLAB Comparison


% MATLAB code for Hammerlindl method
h = 50;            % Net pay thickness (feet)
phi = 0.20;        % Porosity
c = 1.5;           % Formation volume factor ratio
pi = 3000;         % Initial reservoir pressure (psia)
pwf = 500;         % Wellbore flowing pressure (psia)
Bgi = 0.005;       % Initial gas formation volume factor (reservoir scf/scf)

GIP_MATLAB = (7758 * h * phi * c * (pi - pwf)) / Bgi;
disp(['GIP_MATLAB: ', num2str(GIP_MATLAB), ' scf']);

Hammerlindl Method for Gas in Place Calculation using Excel

Basic Theory

Procedures

Excel Implementation

MATLAB Comparison

Comments

Leave a Reply Cancel reply