2] suggests that multiscale methods are a useful tool for purposes of computational efficiency. In this paper we explore a multiresolution approach We consider inverse problems described by that class to solving one dimensional inverse problems. The apof operators which are made sparse under the action proach we take is motivated by the work of Chou, of the wavelet transform [2]. Thus, the inve...

Few production problems strike fear into the hearts of engineers the way scale can. Scale is an assemblage of deposits that cake perforations, casing, production tubing, valves, pumps and downhole completion equipment, thereby clogging the wellbore and preventing fluid flow. Scale, just like the scale found in home plumbing or tea kettles, can be deposited all along water paths from injectors t...

Inherently, confined animal farming operations (CAFOs) and other intense fecal-rich environments are potential sources of groundwater contamination by enteric pathogens. The ubiquity of microbial matter poses unique technical challenges in addition to economic constraints when sampling wells in such environments. In this paper, we evaluate a groundwater sampling protocol that relies on extended...

During the deepwater drilling, complicated gas-liquid-solid multiphase flow will occur if formation gas enters and migrates in wellbore. Through understanding of wellbore behaviors is great importance for blowout prevention well control. Considering dynamic mass heat transfer process caused by alternating ambient temperature field, a model multicomponent fluid deduced developed, including conti...

Method: In this paper, the shallow formation around the borehole is divided into plastic zone and elastic zone considering it under nonuniform in-situ stress. The collapse pressure formula of shallow formation is derived by taking the shrinkage rate of the borehole as the instability criterion. The fracturing pressure calculation model of shallow sediment under non-uniform in-situ stress is der...

Within two hours after discharge began, for a production test in 1989 of well ZCQ-4, pressure variations changed from approximately sinusoidal to a cycle of sudden and complex peak discharge pressures, to 9 bar, separated by irregular pressure declines to 5 bar. Initial cycle periods of 42 minutes evolved to 150 minutes by day 20 of continuous testing, when three of four surge peaks were well s...

Increasing volumes of drilling lateral branches trunks, using the main also put forward need to solve a number new problems. Among them, there are small radial gaps between production string or liner and wall wellbore, which make it difficult ensure tightness annulus. The problem is exacerbated by fact that on an inclined horizontal section always eccentrically displaced relative axis well. The...