This paper summarizes the conditions, applied techniques, results, and lessons of major field gas production attempts from hydrates in past necessity longer term testing with scale years to fulfill gap between currently available information knowledge required for commercial development. The temporal spatial scales test projects employing depressurization have expanded since 2002. results prove...

A mathematical model has been developed to predict the temperature distribution in wellbores either offshore or inshore. It is incorporated the different activities encountered during drilling operations. Furthermore, the effect of drill collar and casings and bit rotating in a well during completion has been considered. The two dimensional approach is presented in the form of a computer progra...

The casing deformation problems are presented over 36 wells (among 112 horizontal wells by 2016) during fracturing processes in Weiyuan-Changning shale gas play in China.1 Subsequent tools could be blocked in the wellbore.2–4 The segments with serious deformation had to be abandoned before completing fracturing operations.5 The casing deformation issues make a great influence on production of s...

Coiled tubing is used in a variety of oil well operations including drilling, completions, and remedial activities. For each of these applications coiled tubing offers the benefits of reduced costs, speed, and reduced environmental impact. Coiled tubing possesses a limitation however, in that it may buckle in service. In this situation the tubing may be damaged, and operations may be delayed or...

Elemental sulfur (S8) is often present in considerable amounts in sour gas reservoirs at the reservoir conditions (pressure and temperature). For the isothermal conditions in the reservoir, the reduction in reservoir pressure below a critical value will cause the elemental sulfur to deposit in the formation. Sulfur deposition can cause severe loss in the pore space available for gas, and in tur...

[1] Over 109 small earthquakes (Mw 0.4–3.9) were detected during January 2011 to February 2012 in the Youngstown, Ohio area, where there were no known earthquakes in the past. These shocks were close to a deep fluid injection well. The 14 month seismicity included six felt earthquakes and culminated with aMw 3.9 shock on 31 December 2011. Among the 109 shocks, 12 events greater than Mw 1.8 were...

This work presents numerical well testing interpretation model and analysis techniques to evaluate formation by using pressure transient data acquired with logging tools in crossflow double-layer reservoirs by polymer flooding. A well testing model is established based on rheology experiments and by considering shear, diffusion, convection, inaccessible pore volume (IPV), permeability reduction...

This paper describes the investigation of a single-well enhanced geothermal system comprised of a downhole thermosiphon and a novel completion design using a downhole heat exchanger. The thermosiphon is a device that takes advantage of the gravity head difference between liquid flowing down the annulus and vapor flowing up the tubing. Without a connection to a large reservoir volume, a downhole...