in the traditional hole drilling method the in-plane stresses are studied in detail and the interlaminar stresses are not taken seriously. the interlaminar stresses on the free edge of composite materials are important and can cause matrix cracking and delamination. inserting holes in composite laminates causes free edges and it can induce interlaminar shear and normal stresses. in this researc...

Directional drilling techniques, based on rotary steerable systems, are used to generate complex curved boreholes. In practice, however, boreholes drilled with such systems often show instability-induced borehole spiraling, which negatively affects the borehole quality and increases drag losses while drilling. As a basis for controller synthesis, we present a directional drilling model in terms...

Soil vapor extraction (SVE) systems are intended to cause substantial volumes of air to flow through the subsurface with the purpose of removing volatile contaminants. The effectiveness of SVE can be influenced by any effect that changes the specific gas capacity (discharge as a function of vacuum) of a well. Skins of low permeability material enveloping a well bore are widely recognized to aff...

In this paper, we apply recent results on disturbance rejection in the interior domain of a class of 2 × 2 linear hyperbolic systems of partial differential equations to the problem of rejecting heave-induced pressure fluctuations at the casing shoe in managed pressure drilling. We show that a PDE model of the drilling dynamics belongs to this class of systems, and derive both state feedback an...

Whilst drilling is the most frequently employed operation of secondary machining for structure joining, delamination is a very serious defect during drilling of fiber-reinforced composite materials,. The evaluation of the delamination damage in the material is important but rather difficult, particularly for carbon fiber-based composites, because their colour makes visual inspection difficult. ...

America). By drilling, coring and analyzing stratigraphic. By drilling, coring and analyzing stratigraphic By drilling, coring and analyzing stratigraphic By drilling, coring and analyzing stratigraphic y drilling, coring and analyzing stratigraphic archives along the Antarctic continental margin, ANDRILL , ANDRILL pursues its primary goal of better understanding the role the primary goal of be...

The study of in situ stress from image logs is a key factor for understanding regional stresses and the exploitation hydrocarbon resources. This work presents comprehensive geomechanical analysis two eastern Algerian fields to infer magnitudes principal components field orientation. Acoustic borehole measurements were used this research aid our development. studied In-Adaoui Bourarhat encompass...

Although Osborn et al. (1) provided important geochemical measurements of dissolved methane in a portion of the Appalachian basin, their report does not fully appreciate the geologic history of this region and misrepresents potential risks of modern drilling and completion techniques used to develop shale-gas resources. The fear that hydraulic fracturing is responsible for methane migration fro...

The distance to failure of the upper crustal rock in prevalent stress field is importance better understand fault reactivation by natural and induced processes as well plan manage georeservoirs. In particular, contemporary state one key ingredients for this assessment. To provide a continuous description 3D absolute geomechanical-numerical models are used. However, magnitude data model calibrat...

The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas...