A critical phase of oil well completion involves positioning cement between the outer surface of a metal casing and the sides of the well. This task is done by injecting a specially formulated cement slurry down the center of the casing and up the sides of the bore hole. Designing these slurry systems is time consuming and expensive because of the variability of the conditions between wells and...

Pooling biospecimens is a well accepted sampling strategy in biomedical research to reduce study cost of measuring biomarkers, and has been shown in the case of normally distributed data to yield more efficient estimation. In this paper we examine the efficiency of pooling, in the context of information matrix related to estimators of unknown parameters, when the biospecimens being pooled yield...

Two-layer metallic sheets have wide applications in various industries due to their superlative characteristics. This paper presents analytical model to investigate the formability of two-layer sheets based on Marciniak and Kuckzinsky (M-K) method using Barlat and Lian non-quadratic yield criterion. FEM simulation is also performed to calculate the forming limits based on bifurcation theory. Fo...

According to the characteristics of high bottom hole temperature and large difference between inner outer walls reservoir casing in process underground coal gasification (underground gasification), field stress model wellbore gas production wells is established based on thermo-mechanical coupling, distribution different steel grades under limit working conditions studied. The results show that:...

Abstract This paper investigates cracking failure of the casing tube. There were longitudinal cracks in heavy oil thermal recovery well occurred an field. The fracture cause was analyzed by macrographic observation, chemical composition analysis, mechanical property test, metallographic scanning electron microscope (SEM) and residual stress calculation. results showed that crack failed originat...

An investigation into the mechanical properties of K55, N80, and P110 steels commonly used for casing drilling was carried out together with microstructural fractographic analysis. The results show that steel consisted almost fully tempered martensite exhibited a synergy combination static tensile, dynamic impact, fatigue crack propagation among three steels, possessing higher limit deeper tole...