Mesfin Belayneh

Designing Drilling Fluids to Combat Circulation Losses for Arctic Environments

Drilling fluid plays a key role in an efficient drilling operation to minimize problems such as wellbore collapse, circulation losses and stuck pipe. Well instability problems are costly as they increase the non-productive time and the overall budget (1) (2). Well instability problems controlled by designing appropriate mud density and fluid properties that controls the well. The fracture sealing ability of a drilling fluid is one very important of the drilling mud.This paper presents design of water-based drilling fluids and results from laboratory experiments to quantify the loss circulation performance of drilling fluids.Because it is preferable to use oil-based muds in some well sections, the paper will also include a recent study on how to minimize losses when using oil based muds. Here uses of micro/nanoparticles have shown to reduce filtrate losses and to build barriers that are more efficient during circulation loss events.All the tests presented are at low temperature, which is suitable for Artic environments.Copyright

Effect of Nano and Micro Sized Particle Additives on the Mechanical Strength of Cement Plug

Cements in oil wells are exposed to high temperatures, a high pressures and a degrading environment. These affect the mechanical strength of the cement over time. Cement is often part of well integrity problems, sometimes creating leak paths to surface, but also allowing sour reservoir gases to corrode casings.Poor cement bond quality and casing corrosion are two fundamental problems with oil well cements. This paper presents the effect of vegetable fiber, nano- and micro particle additives on cement slurry. The mechanical strength of the cement plugs were analyzed through sonic measurement and uniaxial compressive test. The internal structure of the cement plugs were analyzed through Scanning Electron Microscope (SEM).The test results show an improved internal structure, higher load carrying capacity, longer deformation and higher modulus of resilience.© 2015 ASME