Pre-processing of stop pump pressure
test data
Bottom-hole pressure conversion for variable density and flow
During fracturing, different
types of fracturing fluid are injected and sand adding is also required. The viscosity,
density and so on physical parameters of different types of fluid will produce complex flow
in the wellbore，so that the calculation method of converting the wellhead pressure to the
bottom hole pressure is very complicated. According to the principles of mechanical mass
conservation, momentum conservation and energy conservation in wellbore, this project
establishes the vertical pipe flow equation of wellbore considering variable density and
fluid physical property, and adopts Longer-Kut method to solve the equation, so as to ensure
the accuracy of the wellhead pressure converted to the bottom hole pressure, and to provide
guarantee for the correct interpretation and analysis of the stop pump pressure.
Filtering elimination of water hammer pressure after stop pump
The pressure
oscillation produced by stopping pump, that is, water hammer effect, has a great influence
on the pressure and derivative curve in the early stage. In order to better analyze and
explain the stop pump pressure data, it is necessary to process the pressure data after stop
pump fracture by filtering.
Analysis of stop pump pressure data
software
The
bottom-hole pressure solution of multiple stage fracture horizontal well in Laplace space
and physical space
Multi-stage fracturing horizontal well stop pump data analysis
plate drawing
According to the number of
different fractures, different fracture length and different permeability, different
pressure and derivative double logarithmic plate are obtained. Because of the many
parameters in horizontal well fracturing, we propose to manage the graph plate according to
the importance of curve parameters, size order and so on, which is beneficial to improve the
speed of curve simulation.
Stop pump data analysis for each layer of pressure data
Through the
analysis, we can obtain: the half length of each fracture, the diversion capacity, and the
parameters such as permeability, area and average pressure in the SRV area.
Interpretation and evaluation of
report preparation
Based on the test and analysis, combine the drainage reality, the influence of different
drainage methods on the seepage capacity of gas-water reservoir two-phase flow is studied.
At the same time, the stress state is evaluated by using the pressure recovery well test
results.
