SAND RETENTION - CONSTANT DRAWDOWN
Constien & Associates offers sand retention testing designed to meet a variety of conditions. The C&A Constant Drawdown Test will assist the client in identifying promising completion candidates for screen and / or gravel pack. This procedure enables you to quantify critical performance properties of commercial sand control screens including the amount and size of formation sand produced through the screen and loss of screen permeability. Testing procedures are described in SPE 73772.
The first step in sand retention testing is selecting the formation particle size distributions for testing. Typically, multiple formation particle size distributions will be encountered in a single completion. C&A can perform frequency analysis on a complete series of distributions to assist in selecting representative distributions for testing.
The C&A Constant Drawdown Test is an oil flow screen test utilizing a high viscosity oil, that evaluates the performance of the screens in 2 different environments. In the first part of the test, a deposition bed of about 0.5” of formation material on the screen is formed. This simulates the filling of the annulus between the screen and wellbore.
The second part of the test simulates the environment after the annulus area has been filled with formation material and the wellbore stresses increase on the formation and screen or formation, gravel pack, and screen. For each test set, C&A will correlate the test results and prepare MasterCurves for the various sand control screens or gravel packs tested as described in SPE 98363.
Total Produced Solids for Screen and Gravel Pack Tests
From the C&A Constant Drawdown Test Method the following is able to be determined:
The amount of formation material that passes through the screen
The retained permeability of the screen
The size of the particles produced through the screen
The permeability of the formation and formation plus screen at three stress levels
Formation Pack after test - notice holes in formation from sand production. Formation Sand embedded in screen (below and far right).