Backfill device and backfill method for chambers formed during exploitation of natural gas hydrate in seafloor

Abstract

The invention discloses a backfill device and a backfill method for chambers formed during exploitation of natural gas hydrate in seafloor. The backfill device comprises a chamber situation in-situ monitor system, a raw material collection system, a batching system, a pumping and injecting system, and a backfill effect detection system. The chamber situation in-situ monitor system comprises a chamber situation comprehensive measuring device and a chamber situation collection unit; digital signals of the chamber situation collection unit are transmitted to the chamber situation comprehensive measuring device through special cables to perform three dimensional visualization monitoring on complicated chamber situation; The backfill device and the backfill method can realize real-time in-situ monitoring, scheme formulation, material proportioning, backfill construction and effect detection of the chamber in concert with drilling rigs, so as to achieve the purpose of monitoring the formation stability in the mining process.

Description

technical field [0001] The present invention relates to the field of formation stability in the process of seabed hydrate mining, and in particular to a device and method for backfilling chambers generated by seabed natural gas hydrate mining, wherein the backfilling method is also suitable for maintaining oil shale in-situ mining projects stability. Background technique [0002] Natural gas hydrate (Natural Gas Hydrate) is a clean and efficient emerging energy. Its reserves are huge. The reserves of total organic carbon in gas hydrates on the earth are about twice the sum of oil, natural gas and coal, and the resources of gas hydrates in marine areas account for 99% of the total resources. According to surveys, 90% of the world's oceans contain natural gas hydrates, and the continental slopes of the South my country Sea and the East China Sea also show great potential for the development of natural gas hydrates. [0003] In the subsea gas hydrate formation, the hydrate ce...

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Problems solved by technology

The emerging solid mining method also adopts physical methods to cut large pieces of hydrate deposits, and the fragments of the deposits are taken out as a whole. The absence of hydrate deposits will form larger chambers on the seabed. If the scale of the chambers is allowed to increase, it will The structural strength of the mining work area is reduced, and the chamber collapses, causing major safety accidents

[0005] In terms of seabed hydrate exploration and development research, the current research on seabed natural gas hydrate development at home and abroad is mainly in the development stage of hydrate mining methods and equipment, and the existing hydrate exploration and mining methods are faced with the formation of chambers leading to hydrate occurrence. The stability of the strata and the overlying stratum is reduced, and the engineering safety cannot be guaranteed

In terms of chamber backfill research, the current backfill design is mainly concentrated in inland mines, and because the seabed has special environments such as high pressure, submersion, and low temperature, and hydrate-occurring formations are different from ordinary formations in terms of strength, porosity, and water content, etc. The method and process of backfilling the chambers located in the hydrate layer on the seabed are more complicated

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