Wellbore instability is the primary technical problem that restricts low-cost drilling of long-interval horizontal wells in shale formation Jidong Oilfield. Based on evaluation mineral composition, structure and physicochemical properties shale, this paper investigates mechanical behavior characteristics under fluid action by combining theoretical analysis, experimental numerical simulation. Du...

In the last decades, the problem of perforation damage has been considered as the major factor for the reduction of oil productivity. Underbalance perforation is considered as one of the best means to minimize or overcome this problem. By maintaining wellbore pressure lower than formation pressure, perforation damage could be minimize or eliminated. This can be achieved by the use of nontraditi...

Since hydraulic fractures exhibit a strong tendency to propagate in a plane normal to the least principal stress, the preferred plane of propagation under thrust stress regime (Sh > Sv) conditions is horizontal. This can lead to complications in applying the hydrofracture stress measurement technique as horizontal fractures do not directly sample the horizontal stress field. Recent experiences ...

This investigation presents the effect of various parameters on foam stability and its rheological properties. The underlying idea of this experiment is generating of drilling foam with uniform bubbles. The main problem of foam using is controlling its stability during field application. The most important parameters which cause Instability in foam are gravity drainage, gas diffusion and bubble...

Purpose. To increase the stability of wellbore during its construction in unstable rocks. Methodology. solve set tasks, an integrated approach is used work, which includes critical analysis and generalization scientific technical achievements combination with theoretical experimental research. Findings. Factors influencing borehole walls conditions prone to rock slides falls are analyzed. Exped...

Horizontal wells can significantly improve the gas production and are expected to be an efficient exploitation method for industrialization of natural hydrates (NGHs) in future. However, near-wellbore hydrate is highly prone decomposition during drilling process, owing disturbance aroused by factors such as fluid temperature, pressure, salinity. These issues result engineering accidents bit sti...