Research and application of high−temperature drilling fluid designed for the continental scientific drilling project of Songliao Basin, China

ABSTRACT

Well Songke−2 is the main hole of the Continental Scientific Drilling Project of Songliao Basin, China, and its bottom hole temperature is estimated to exceed 240°C in the fourth spud at the well depth of 5800 m. To ensure that the drilling fluid could meet the demand of high temperature resistance, different components, including clay, filtration reducers and anti−collapse additives, of the high–temperature drilling fluid system were optimized through thermal stability tests. Comprehensive test results suggested that the optimal bentonite content to be 4% (w/v). Compared with other materials of the same type, polymer filtration reducers SO−1 and HLW−1, as well as sulfonation additive LOCKSEAL were demonstrated to have stronger resistance to high temperature. The proposed high temperature drilling fluid formula exhibited good thermal stability, rheological behaviour, anti−contamination capacity and shale inhibition property. Finally, a great success of the formula was practically obtained in the field application during the following−up core drilling project.

KEYWORDS:

• Songliao Basin
• Continental scientific drilling
• high−temperature drilling fluid
• core drilling
• high temperature stability

Additional information

Funding

This work was supported by the China Geological Survey Projects [No.DD20160209]; Sinoprobe-05 [No. 201011082].

Notes on contributors

Wenlong Zheng

Wenlong Zheng, a pHD student in China University of Geosciences(wuhan), majoring in Goelogical Engineering(Drilling Engineering), participated in the whole process of drilling the Well SK2(the main hole of the Continental Scientific Drilling Project of Songliao Basin, China).

Xiaoming Wu

Xiaoming Wu, a professor in China University of Geosciences(wuhan), mainly engaged in drilling engineering related research work.

Yuming Huang

Yuming Huang, a pHD student in China University of Mining and Technology(beijing), majoring in Engineering Management(Geological Engineering).