As an important slurry material for water-based drilling fluids, montmorillonite has been widely used in oil because of its excellent properties such as expansibility, dispersion and suspension, making, cation exchange adsorption. However, at a certain temperature pressure, will transform into illite, chlorite other minerals, changing the fluids. In order to systematically summarize sort out cu...

Control of micro-organisms during completion of hydraulically fractured wells is a significant component in successful development of a production system. Detrimental bacteria—“bad bugs”—such as sulfate-reducing bacteria (SRB) introduced into the reservoir during drilling or completion, can facilitate biogenic sulfide production, resulting in souring of production fluids and gas, iron sulfide f...

MECHANISMS ..............................................................................................................2 INTRA-MOLECULAR DIPOLE-DIPOLE INTERACTIONS.....................................................4 INTER-MOLECULAR DIPOLE-DIPOLE INTERACTIONS .....................................................5 SPIN-ROTATION INTERACTIONS........................................................

There has been an increasing interest in seafloor exploitation such as mineral mining in deep-sea hydrothermal fields, but the environmental impact of anthropogenic disturbance to the seafloor is poorly known. In this study, the effect of such anthropogenic disturbance by scientific drilling operations (IODP Expedition 331) on seabed landscape and megafaunal habitation was surveyed for over 3 y...

This paper presents main results of a shale stability study, related to the understanding of shale/ fluid interaction mechanisms, and discusses shale strength correlation. The major shale/ fluid interaction mechanisms: Capillary, osmosis, hydraulic, swelling and pressure diffusion, and recent experimental results are discussed. Factors affecting the shale strength are discussed, and a sonic com...

The accurate prediction of wellbore temperature distribution helps to accurately estimate well pressure profile and bottom-hole pressure (BHP) which is important in the under-balanced drilling (UBD) operation. In this paper effect of temperature variation due to heat transfer of drilling fluid with the formation and also oil and gas production from the reservoir into the annulus in under-balanc...

In China’s unconventional oil drilling, horizontal wells are one of the main forms water-in-oil drilling fluid have been widely used due to their stable performance and excellent lubricating properties. To reduce high cost fluids at site, further pressure cuttings processing, meet requirements environmental protection, an oil-based system with a low oil-water ratio was developed. Based on resea...