Single phase water state testing requirements:
Adopting the downhole
shut-in method, the surface direct reading test technology, open-close-open drainage,
constant flow and pressure drop drainage is carry on during open well drainage stage (slow
drainage for the first open well, quick drainage for the second open well), under the
condition that the gas is not desorbed, the shut in pressure recovery test is carried out,
and the pressure is reduced near the desorption pressure and the constant pressure drainage
process will last for 30 days to test the change of water permeability in the process of
constant pressure drainage, and to test the formation pressure recovery condition again when
we guarantee the gas is not desorbed.
For the collection of data points for open well flowrate pressure
and shut-in pressure recovery, in order to maintain synchronization with the tubular pumps,
the same sampling time intervals are used: one data point is taken every 5 minutes for the
down, open well drainage and shut-in pressure recovery stages.
Test results
To verify the influence of the after-pressure discharge mode on
the seepage capacity of gas wells.
The gas saturation of fracturing fractures with different gas
discharge pressure after casing pressure is compared.
To verify the change of the seepage capacity of gas well and
water in the process of stable casing pressure.
Compare the formation pressure recovery condition before and
after casing pressure in the same well.
To verify the water producing capacity of the drainage process
layer prior to stratified combined production and desorption.
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.
