Changes

==Bottom hole temperatures==

==Bottom hole temperatures==

Extremely high bottom hole temperatures can occur in deep wellbores or in areas of abnormally high [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=geothermal%20gradient geothermal gradient]. These excessively high bottom hole temperatures (greater than [[temperature::250°C]]) can cause drilling problems because of the accelerated thickening of water-based drilling fluids. The increase in viscosity and density of the drilling can may result in the following:

Extremely high bottom hole temperatures can occur in deep wellbores or in areas of abnormally high [http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=geothermal%20gradient geothermal gradient]. These excessively high bottom hole temperatures (greater than [[temperature::250°C]]) can cause drilling problems because of the accelerated thickening of [[Drilling_fluid#Water-based_muds|water-based drilling fluids]]. The increase in viscosity and density of the drilling can may result in the following:

* Reduction in penetration rates

* Reduction in penetration rates

* Stuck tools

* Stuck tools

This problem can be mitigated by using oil-based muds.

This problem can be mitigated by using [[Drilling_fluid#Oil-based_muds|oil-based muds]].

==See also==

==See also==