The latest stage of gas field development is characterized by some exploitation complications, related to reducing of gas rates and as a consequence a water accumulation in gas-gathering systems (in-field gas pipelines). It leads to a formation of ice and/or hydrate deposits in contact with a cold wall of pipeline with negative (on Celsius) temperature as a result of an environmental impact. Analysis of gas-gathering systems of the Yamburg field (Cenomanian horizon) revealed qualitative differences between ice and hydrates deposition. For instance, ice formations are characterized with higher locality due to significant water accumulations on the lower section of the pipeline and ice growth at the wall of pipeline. Thus, liquid plugs play a key role in the formation of ice plugs that block pipeline's cross-section, reduce the stability of gas collection system's technological regime and gas production. The purpose of this work is to discuss some technical solutions, efficiently eliminating the accumulation of liquids in gas-gathering systems while having a low exploitation expenses, simple realization and flexibility of applications compared to existing ways. A technical solution for local diameter reduction facilitates the water plugs removal at most critical in terms of ice formation. An approach, based on the application of lay-flat polymer sleeve for local pipe diameter reduction allows the increasing velocity of gas-liquid flow at a given pipe sector for providing stable liquid removal without its accumulation. Target pipe areas suitable for the technology are chosen based on hydrodynamic modeling, accounting for the actual pipeline route. Application of an ejector unit and in-tube separator enables to independently decrease pressure at the pipeline by 1.5-3.5 times. This leads to increase of gas-liquid velocity by 2-3 times, which leads to liquid removal. This allows reduction of methanol consumption, which is used for water freezing prevention. The proposed technologies allow variations in realization dependently on requirements for exploitation modes and for time-changing parameters of gas-gathering systems operation. These technologies can be considered as a part of a complex strategy for gas-gathering system reconstruction at the stage of production drop.
|Publication status||Published - 2017|
|Event||SPE Russian Petroleum Technology Conference 2017 - Moscow, Russian Federation|
Duration: 16 Oct 2017 → 18 Oct 2017
|Conference||SPE Russian Petroleum Technology Conference 2017|
|Period||16/10/17 → 18/10/17|