EP 3642297 A1 20200429 - DRILL FLUID AND METHOD FOR TUNNELING
Title (en)
DRILL FLUID AND METHOD FOR TUNNELING
Title (de)
BOHRFLÜSSIGKEIT UND VERFAHREN ZUR TUNNELUNG
Title (fr)
FLUIDE DE FORAGE ET PROCÉDÉ DE TUNNELLISATION
Publication
Application
Priority
- US 201762524361 P 20170623
- CA 2018050777 W 20180622
Abstract (en)
[origin: WO2018232532A1] A method for drilling a tunnel through a formation must address environmental concerns. One tunneling method comprises the steps of: preparing a mixed metal-viscosified drilling fluid including bentonite, a mixed metal viscosifier and controlling pH to 8.5 to 9.5 to permit a reaction between the bentonite and the mixed metal viscosifier; adding at least one of: (i) calcium sulfate and (ii) a potassium salt; and pumping the drilling fluid while drilling the tunnel with the pH lowered to 7 – 9. The amount of mixed metal viscosifier used can be limited such that the weight ratio of mixed metal viscosifier to MBT reaches up to 1:30. In the event that there is a problematic increase in viscosity, a non-toxic anionic thinner can be added to the drilling fluid. One such anionic thinner is a polyacrylate.
IPC 8 full level
C09K 8/24 (2006.01); E21B 21/00 (2006.01); E21B 21/06 (2006.01); E21D 9/11 (2006.01); E21D 9/13 (2006.01)
CPC (source: EP)
C09K 8/16 (2013.01); E21B 21/003 (2013.01); E21D 9/04 (2013.01)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
WO 2018232532 A1 20181227; AU 2018286661 A1 20200213; AU 2018286661 B2 20201203; AU 2021201364 A1 20210318; AU 2021201364 B2 20221222; AU 2021201374 A1 20210318; AU 2021201374 B2 20230323; CA 3030574 A1 20181227; CA 3030574 C 20191231; CA 3061085 A1 20181227; CA 3061085 C 20200908; EP 3642297 A1 20200429; EP 3642297 A4 20210317; MA 49467 A 20210317
DOCDB simple family (application)
CA 2018050777 W 20180622; AU 2018286661 A 20180622; AU 2021201364 A 20210302; AU 2021201374 A 20210303; CA 3030574 A 20180622; CA 3061085 A 20180622; EP 18819655 A 20180622; MA 49467 A 20180622