CN2733262Y - Well top installation for geothermal tertiary sandstones recharge - Google Patents

Abstract

The utility model particularly relates to the technique of recharging geothermal wells in the engineering of developing and utilizing geothermal resources, which relates to a well top device for recharging geothermal tertiary sandstones. A recharge system is composed of a first stage thick filter set and a second stage fine filter set which are connected in series with a pressure recharging pump and a forcing exhaust tank, wherein, the first stage thick filter set and the second stage fine filter set are connected in parallel. Geothermal fluid firstly enters the first stage thick filter set which has the filtration accuracy of from 50 to 80 mu meters, and then the geothermal fluid enters the second stage fine filter set which has the filtration accuracy of from 3 to 5 mu meters. The filter element material is a filter element which is made of the third generation of polyethylene by sintering or a filter bag. Water quality can be basically guaranteed after the two stages of filtration. The utility model can prevent the air lock due to physic causes, microorganism, chemical causes, etc., and can increase the recharging rate by more than 30%. The utility model has the advantages of convenient system assembly and debugging, simple maintenance and complete monitoring means. Though the system aims at sandstone strata, the system is also suitable for other strata, such as base rocks, etc. The utility model can realize the rational development and protection for the tertiary geothermal resources.

Description

The wellhead assembly that is used for geothermal tertiary system sandstone recharge

Technical field

The utility model belongs to geothermal energy resources and develop and uses engineering, is specifically related to the recharging technique of geothermal well.

Background technology

At present, exploitation and utilization of geotherm resources has formed a comparatively ripe industry, particularly geothermal heating and the utilization of water resource, has greatly spurred the development of related industry.The exploitation target zone of geothermal energy resources mainly concentrates on mist fan mountain group and the hot reservoir of the 3rd sandstone that is.But because the characteristic of the hot reservoir of sandstone rock stratum, recharge in the process because the mass transfer between forming to the dissolving of unsaturated mineral under the fixed temperature and secondary mineral, and the dissolution precipitation of temperature rising mineral, make and in the hot reservoir of sandstone recharges, run into very big difficulty, the subject matter that is occurred has: 1. floating thing stops up: the suspension content of water is too high can to stop up the hole of porous media owing to inject, thereby the water recharge capacity of well is constantly reduced up to recharging; 2. microorganism is stopped up: injecting microorganism water or local may form biomembrane in breeding rapidly around water injection well under the suitable condition, and the blocking medium hole reduces the water transmitting ability in aquifer; 3. chemistry stops up: change when injecting coolant-temperature gage, can produce separating out of chemical substance, form chemistry and stop up water in underground passage; 4. bubble blocks: when well is gone in water filling, under certain mobility status, may carry a large amount of bubbles secretly in the water, simultaneously the dissolved gas in the water may Yin Wendu, the variation of pressure and discharging.In addition, also may generate gaseous matter because of biochemical reaction.

Summary of the invention

In order to solve the blockage problem of physics, chemistry, gas, the purpose of this utility model is to adopt the method for sediment outflow, filtration, degasification to propose that a kind of to be used for the 3rd be that sandstone recharges wellhead assembly.

Below in conjunction with accompanying drawing technology contents of the present utility model is narrated.Be used for the geothermal tertiary system sandstone recharge well head system, mainly have desander 1, strainer 2, recharge pump 3, exhaust tank 4, valve 5.Desander 1 is installed in the production wellhead place, and desander mainly leaches fine sand in the hot reservoir of sandstone.Desander 1 is connected in series with coarse filter group 2-1, fine filter 2-2.The underground heat current are tangentially imported by desander 1 cylindrical shell side, and on the counter steer, the cylindrical shell central authorities that flow through entered strainer 2 through gutter after high speed rotated into cone end in the desander cylindrical shell.This process can effectively prevent from the sand grains in the sandstone formation brought into recharges filtration system, thereby alleviates the work load of strainer 2.Because the amount of recharging is with adopting quantitative changeization, for the ease of installing, unpicking and washing and change filtrate, screen material is wanted heatproof and withstand voltage.Strainer 2 is worked with a plurality of split parallel waies, in import and export thick, fine filter 2-1,2-2 the maintenance valve is housed all.In case equipment breaks down or when changing filtrate, can not influence and recharge.For reused filtrate, in backwash process, the clean water of must use having filtered.When fluid was flowed through strainer 2, flow velocity reduced, and pressure also changes to some extent, and former unsaturated portion gas may discharge, and therefore also automatic exhaust valve will be set on all strainer 2 tops.Coarse filter group 2-1 and fine filter group 2-2 that the utility model adopts two-stage to constitute with parallel way, again with recharge pump 3, exhaust tank 4 composes in series recharge system.After injection water after filtering entered exhaust filling 4, because caliber changes, flow velocity reduced, and can further discharge by forced into solution gas, and the automatic exhaust valve on exhaust tank 4 is emitted.The back of exhaust tank 4 is provided with different branches and recharges pipeline, is made up of valve 5-2,5-3 and recharges major trunk roads, and valve 5-4 and 5-5 and 5-1 and 5-6 are parallel to the two ends of valve 5-2,5-3, and floss hole is located between valve 5-1, the 5-6.Wherein by valve 5-4 and 5-5 form the road be mainly used in the installation automatic monitoring system so that automatically pressure, the amount of recharging, temperature and recharge well water level are recharged in monitoring, understand the dynamic change of the process of recharging at any time.Valve 5-1 is mainly used in relict sediment or anvil cinder in the flushing pipe to the floss hole branch road.In the utility model, desander 1 adopts the spiral-flow type desander; The filter core of strainer 2-1,2-2 adopts the polyethylene sintering processing to make; Recharge pump 3 and recharge pump for pressurization; Exhaust tank 4 is the forced action type exhaust tank.

Description of drawings

Accompanying drawing is a plant system drawing of the present utility model.

Wherein: desander-1; Coarse filter 2-1; Fine filter 2-2; Recharge pump-3; Exhaust tank-4; Valve-5.

The specific embodiment

Below by drawings and Examples the utility model is described further.

It is that sandstone recharges that China just begins to pay close attention to the 3rd at early eighties, and tests at geothermal wells such as Tanggu, huge ports, but because unresolved blockage problem, recharge rate in time can be more and more lower, and recharge rate only reaches about 20-30%, have in addition can't recharge again.By the enforcement of the utility model in the Tianjin Dongli District China hot demonstration project in safe agriculture field, the amount of adopting is 60t/h, and the amount of recharging is 50t/h, and recharge rate can reach more than 80%.Owing to may have particle diameter bigger metal slag particle or sediment in the recovery well pipeline, filter process adopts the filter core of same precision can add the big filter load, increases running cost.Therefore for present embodiment, geothermal fluid at first enters the coarse filter group 2-1 that the first order is composed in parallel by three strainers, and filtration yield is 15-20t/h; The coarse filtration precision is 50-80 μ m, and material for core is third generation polyethylene sintered filter core or filter bag.After one-level was filtered, the particle of greater particle size was filtered, and has guaranteed water quality substantially.Then geothermal fluid enters the fine filter group 2-2 that the second level is composed in parallel by three strainers through pipeline, and filtering accuracy is 3-5 μ m, and material for core is a third generation polyethylene sintered filter core.Because the filtering accuracy height, the suspension in the water, bacterium, chemistry are separated out the molecule of crystallization etc. and can be filtered.In design, the filtrate in the strainer can adopt disposable and the two kinds of filtrates that repeatedly recoil, and the filtrate in the strainer 2 has adopted disposable recoil filtrate in the present embodiment.Of the present utility model recharging is divided into dual mode substantially, and one for recharging naturally, and the 2nd, pressurization is recharged.Naturally recharge is that pressure and gravity by system self recharges.The shunt valve of recharge water this moment in recharging pump 3 carries out nature and recharges.Can adopt pressurization to recharge pump 3 in the time of can not normally implementing when recharging naturally.For gas contained in the GEOTHERMAL WATER is fully discharged, to prevent in the process of recharging, forming bubble, cause gas stifled, therefore work as GEOTHERMAL WATER and enter before the recharge well, be introduced into exhaust tank 4.Between valve 5-2 and 5-3, water meter is housed, between valve 5-4 and 5-5, electromagnetic flowmeter is housed, automatically the monitoring amount of recharging.Initial stage, for relict sediment or anvil cinder in the abundant flushing pipe, it was underground to prevent that residue from pouring into, and stops up the underflow passage when recharging.Open valve 5-1 branch road is closed other valve simultaneously, and the water that will have residue discharges by lateral, is fully rinsed well until pipeline.When recharge rate descended, recharge well need carry out Hui Yang, and at this moment Open valve 5-6 closes other valve simultaneously, and the waste water of Hui Yang is prolonged discharge of pipes.The pressure of paying close attention to simultaneously between the two-stage filter changes, because change to judge whether filtrate needs to clean and change in the strainer by pressure.

The characteristics that the utility model has and beneficial effect: can prevent from being produced by reasons such as physics, microorganism, chemistry Vapour lock, it is about more than 30% to improve recharge rate, can realize that to the 3rd be the target of geothermal energy resources reasonable development and protection. System's installation and debugging are convenient, safeguard that simply monitoring means is complete. Although this is practical for sandstone formation, but still suitable The rock behavio(u)r that is used for other stratum is such as basement rock etc.

Claims (4)

1. the wellhead assembly that is used for geothermal tertiary system sandstone recharge, mainly have desander (1), strainer (2), recharge pump (3), exhaust tank (4), valve (5), it is characterized in that desander (1) is connected in series with coarse filter group (2-1), adopt coarse filter group (2-1) and the fine filter group (2-2) that two-stage constitutes with parallel way and recharge pump (3), exhaust tank (4) composes in series recharge system.

2. according to the described wellhead assembly that is used for geothermal tertiary system sandstone recharge of claim 1, it is characterized in that the maintenance valve all is equipped with in the import and export of described thick, fine filter (2-1), (2-2), described exhaust tank (4) top is furnished with automatic exhaust valve.

3. according to claim 1 or the 2 described wellhead assemblies that are used for geothermal tertiary system sandstone recharge, the back that it is characterized in that described exhaust tank (4) is provided with different branches and recharges pipeline and automatic monitoring system, by valve (5-2), (5-3) and form and recharge major trunk roads, valve (5-4) and (5-5) and (5-1) and (5-6) be parallel to the two ends of valve (5-2), (5-3), floss hole is located between valve (5-1), (5-6).

4. according to claim 1 or the 2 described wellhead assemblies that are used for geothermal tertiary system sandstone recharge, it is characterized in that described desander (1) adopts the spiral-flow type desander, the filter core of described strainer (2-1), (2-2) adopts the polyethylene sintering processing to make, the described pump (3) that recharges recharges pump for pressurization, and described exhaust tank (4) is the forced action type exhaust tank.