|Minutes of the TG on Dynamic Settling
Hyatt Regency Hotel – San Antonio
20 January 2009
TG Members in Attendance
Robert Beirute - chairman
The chairman opened the meeting at 11:00 hrs by reviewing the minutes of the meeting in Calgary in June 2008, including the charge to the TG.
Prepare a technical report defining test methods and procedures applicable for determining the dynamic settling characteristics of cement slurries, spacers and drilling fluids under simulated well conditions.
The chairman reported that he collected the three testing methods as decided in the Calgary meeting:
Helical Screw Test
The chairman indicated that the Composite Dynamic Settling Test (Amoco) is the result of a combination of Amoco-like test methods he received from several TG members.
Regarding discussion of the SLB Test method, it was pointed out that the first part, which includes a10 min shutdown period, is a static settling test. The second portion of the test is a dynamic test. On the dynamic part of this test, the chairman commented that in his experience, the many blades of the standard paddle and the 150 rpm can keep solids in suspension and therefore not give a good indication of dynamic settling tendencies. That is the reason Amoco developed the Amoco test. Next, the chairman asked Terry Dammel to rewrite the procedure to only address the dynamic behavior, eliminating from the present document, the portion that is considered a static settling test. There was also a discussion on the possible use of a pycnometer to measure the density of a highly gelled cement slurry after the test (70+ Bc but not set). It was also pointed out that the measured densities after the test need to be compared to the design density of the cement slurry.
On the Helical Screw Test, several questions arose that could be answered since Nevio could not make the meeting. Further clarification will be required from Nevio in the future. Some of the questions included: differences observed when rotating the screw vs. the cup, ways of sampling the fluid after the test and observed gelation (vs. settling) on the screw.
The next step is to run cooperative tests. The following labs volunteered to run the tests:
SLB in Houston
Halliburton in Duncan
BJ in Tomball
Craig Gardner volunteered to design the cement slurries to be tested. One with good dynamic settling properties, and another with poor dynamic settling properties.
The meeting was adjourned at 12PM.