Abstract Wellbore instability is frequently encountered in the process of shale oil drilling. Due to anisotropic strength characteristics shale, most conventional models are not suitable for wellbore stability analysis layered formation. In this paper, taking continental north Songliao Basin as research object, elasticity and parameters measured experimentally. Based on pore elastic mechanics, ...

Borehole instability problems are commonly encountered while drilling highly deviated and horizontal shale gas wells within the formations associated with high-dip bedding planes. An integrated rock mechanical study is described in this paper to evaluate risk of borehole area. First, a set uniaxial compressive tests carried out measure strength shales on cores different angles between load dire...

This paper describes a combined field, laboratory, and numerical study of electromagnetic borehole flowmeter measurements acquired without the use of a packer or skirt to block bypass flow around the flowmeter. The most significant finding is that inflow through the wellbore screen changes the ratio of flow through the flowmeter to wellbore flow. Experiments reveal up to a factor of two differe...

In order to carry out a series of key basic researches, a scientific ultra-deep drilling plan is being undertaken in China. Wellbore temperature is one of the key factors during the drilling process. In this paper, we established a twodimensional transient numerical model to predict the ultra-deep wellbore temperature distributions during circulation and shut-in stages. The simulation results i...

We investigate the initiation and early-stage propagation of an axi-symmetric hydraulic fracture from a wellbore drilled in the direction of the minimum principal stress in an elastic and impermeable formation. Such a configuration is akin to the case of a horizontal well and a hydraulic fracture transverse to the well axis in an open hole completion. In addition to the effect of the wellbore o...

Stress state analysis to casing-cement sheathformation system (CCSFS) is the foundation of the wellbore integrity design and examination. Many elastic mechanic models have been established to calculate the stresses and displacements of CCFS, but all analytical models and most finite element models took no account of the initial loaded state, and ignored the initial stresses and displacements on...

Understanding and quantification of wellbore skin improves our ability to accurately measure or estimate hydrologic parameters with tests at wells such as pumping tests, flowmeter tests, and slug tests. This paper presents observations and results from a series of field, laboratory, and modeling tests which, together, explain the source of wellbore skin at wells at a research wellfield and whic...

Wellbores drilled in igneous formation with weak interlayers face significant risk of instabilities. This study aims to investigate the underlying mechanisms these instabilities by employing a combination rock mechanics tests and numerical simulation techniques. The mechanical properties rocks are evaluated determine core strength parameters analyze impact drilling fluid immersion on strength. ...

An Offshore China/South China Sea operator wanted to optimize the use of rotary steerable drilling assembly, simplify and reduce operational steps, and provide a larger reservoir wellbore. The operator elected to drill a single 8.5” wellbore and, in order to address a variety of issues and potential problems, change from a Cloud Point Glycol Drilling Fluid to a DrillIn Fluid (DIF) at the reserv...