CN108301809A - A kind of coal bed gas well dynamic adjustment pump extension discharge and mining method - Google Patents

Abstract

The invention discloses a kind of coal bed gas well dynamic adjustment pumps to hang discharge and mining method, includes the following steps：(1) it is directed to height stream kill-job, the time in quantitative forecast hydrodynamic face arrival coal seam is required according to mining system, the well for liquid level in pump detection period being still not achieved coal seam position above carries on pump extension to coal seam；In each pump detection and workover, hung according to stream pressure situation adjustment pump；(2) by the creation data analysis acquired by hydrodynamic face, indicator diagram measurement, finding out the well of low yield liquid, low submergence due to stratum feed flow deficiency, deepening pump and hang, the suction inlet of pump is uniformly lowered into coal storage layer hereinafter, and being taken out between implementation.The present invention is hung by dynamic adjustment pump, under the premise of meeting gas well liquid loading needs, and then is realized and is dropped this, subtracts expense, the purpose of synergy.

Description

A kind of coal bed gas well dynamic adjustment pump extension discharge and mining method

Technical field

The invention belongs to Coal-seam Gas Recovery Technologies fields, and in particular to a kind of coal bed gas well dynamic adjustment pump extension mining side Method.

Background technology

Coal bed gas production is the process of a drainage and step-down, during CBM exploration and development, by nearly 7 years survey Development Practice is visited, five section of three pressure type mining working system is gradually explored：Quick drainage pressure reducing period, voltage stabilizing drainage period, slowly drop Press drainage period, single-phase flow draining tailend, production plateau.Therefore, before gas well enters production plateau, the long period is had Drainage period；After entering production plateau, a part of well will appear gas phase single phase fluid flow, shows as aerogenesis and rises, produces under water Drop or even no liquid output.Think that gas well has formed enough pressure drop faces by very long single-phase drainage period early period Product, even if not having liquid output, the methane molecule largely desorbed remains under the action of pressure difference and concentration difference, by pressure break change The seepage channel made and formed, migration come out, and keep high yield, stable yields.

Yanchuan south development well is to ensure that coal seam can be fully depressured at present, and continuing to use industry experience will pump under coal seam. But from the point of view of the produce reality of the slow mining in gas field, 1000 days or so period is produced on gas well, and part well is in 2MPa or so Realize voltage stabilizing stable yields, liquid level reach coal seam to undergo 1-2 pump detection period even it is longer, need not too early will pump down toward coal seam it Under.Deep increase is pumped simultaneously and also exposes series of malpractice, not only increases tube rod dosage, Increased Load, but also tube rod pump stays coal Perishable well section near layer, the optimal control for preventing and entering well material to coal dust, eccentric wear, corrosion bring pressure.

Invention content

To solve the above-mentioned problems, the present invention provides a kind of coal bed gas well dynamic adjustment pumps to hang discharge and mining method.

The technical scheme is that：A kind of coal bed gas well dynamic adjustment pump extension discharge and mining method, specifically includes following steps：

（1）Kill-job is flowed for height, the time in quantitative forecast hydrodynamic face arrival coal seam is required according to mining system, in pump detection period The well that coal seam position is still not achieved in liquid level above carries on pump extension to coal seam；In each pump detection and workover, according to stream pressure situation adjustment Pump is hung；

（2）By analyzing the creation data acquired by hydrodynamic face, indicator diagram measurement, low yield due to stratum feed flow deficiency is found out The well of liquid, low submergence is deepened pump and is hung, and the suction inlet of pump is uniformly lowered into coal storage layer hereinafter, and being taken out between implementation.

Further, extraction takes 22 between described:00-8:00 opens pumping, remaining time stops the working system of well；For not producing liquid Well, stopping finding time can be appropriately extended.

The beneficial effects of the invention are as follows：

1, it is hung by above carrying pump to height stream kill-job, the coal dust, eccentric wear, corrosion and scaling etc. faced in gas well liquid loading can be effectively improved Problem：1. increasing the stroke that coal dust enters oil pipe, the settling amount inside oil pipe is reduced, coal dust holddown probability is reduced；2. reducing The load of roofbolt improves the stress of tube rod, delays eccentric wear；3. avoiding coal seam nearby high flow rate, high temperature, high corrosion ring Border delays tube rod to corrode；4. reducing into well casing bar, premature corrosion fouling is avoided, reduces tube rod replacement amount；

2, it is hung by deepening pump to low flow pressure well, on the one hand it is possible to prevente effectively from because submergence is too low, leads to oil pipe outlet；It is another Aspect, and ensured the decline space of flowing bottomhole pressure (FBHP)；Under the premise of ensureing that tolerance is stablized, produced in conjunction with pumping between implementation, really Protecting in pit shaft has certain submergence, flowing bottomhole pressure (FBHP) that can also keep stable；

3. the difference of time-of-use tariffs is rationally utilized, it can be cost-effective to the greatest extent.

Description of the drawings

Fig. 1 is to prolong 6-46-12 well production curves.

Fig. 2 is to prolong 1-6-8 well production curves.

Specific implementation mode

Present disclosure is further elaborated with reference to specific embodiment, but embodiment is only of the invention Better embodiment, therefore the equivalence changes that all features and principle according to described in present patent application range are done, are included in Within the scope of present patent application.

Background introduction：Yanchuan South block is located at Eastern Margin of Ordos Basin, the monoclinal structure that generally a west is inclined；Middle part two Block is divided into Tan Ping structural belts and ten thousand Golconda structural belts by east northeast-Nan Xi to tomography.Main force's reservoir is Shanxi group 2# coals, thickness Greatly, air content is high, most of buried depth range 800-1500m, is in coal bed gas favorable exploration depth bounds.Because of reservoir buried depth Difference, coal bed gas draining the pressure reducing period time length be also not quite similar.

Wherein have the characteristics that pumping pressure is high, desorption pressures are high, stratum production liquid is low in ten thousand Golconda structural belt reservoirs, to have reached The row of returning to 60% leads, and needs 300-450 days drainage and step-down phases, this stage flowing bottomhole pressure (FBHP) is down to 6.5MPa or so；It subsequently enters Slowly decompression drainage period, general 150-300 days of this period, stream pressure drop to about 5.5MPa；Production plateau is subsequently entered, at this time Site requirement pressure control fixed output quota mining, stream pressure drop width are smaller.Therefore, ten thousand Golcondas construction is taken up and takes out stream and press high well, into Before entering production plateau, often there is the drainage and step-down phase of long period.

Take measures one：When gas well carries out pump detection and workover, finding the well still has higher high stream kill-job, according to mining system Degree requires quantitative forecast hydrodynamic face to reach the time in coal seam, and liquid level in this pump detection period is still not achieved on the well of coal seam position Pump is carried to hang；In next pump detection and workover, situation is pressed according to stream, then adjusts pump and hangs.

Implementation result：The annual pump that above carries hangs 54 wells within 2016, and individual well averagely above carries about 104.6m, reduces oil pipe 10.9 Root, sucker rod 13.1, accumulative minimizing oil pipe usage amount 588 reduce sucker rod usage amount 706, save oil pipe expense 588 × 455=267540 yuan, 706 × 163=115078 yuan of sucker rod expense, pumping unit day power consumption averagely declines 1.4 degree, saves within 1 year 24834.6 yuan of 1.4 × 365 × 54 × 0.9 ≈ of the electricity charge adds up direct saving material and power consumption cost 267540+115078+ 24834.6 40.75 ten thousand yuan of ≈.

In addition, in 54 wells time implemented this year, has three mouthfuls of wells and be excused from a college course the phase by original averagely 168 days, extend to 379 It, substantially exceeds being excused from a college course the phase for its last time, and still normally producing at present, the job execution expense about 2.6 × 3=7.8 ten thousand of saving Member, and gas well mining continuity is greatly improved, it is specific as shown in table 1：

Table 1 above carries pump and hangs the comparison of the front and rear part well condition of production

Wherein prolong 6-46-12 wells production curve as shown in attached drawing 1.

Take measures two：By analyzing the creation data acquired by hydrodynamic face, indicator diagram measurement, find out because of stratum feed flow The well of insufficient and low liquid, low submergence.The universal submergence of high-yield well of some production times morning is low, causes pump intake pressure low, makes Liquid is not even produced at Liquid output is few, causes pump efficiency low；Such well easily causes the phenomenon that oil pipe outlet.For this type well, In produced on-site, we mainly deepen pump extension by the way that the suction inlet of pump to be uniformly lowered under payzone, on the one hand can have Effect avoids, because submergence is too low, leading to oil pipe outlet；On the other hand, and the decline space of flowing bottomhole pressure (FBHP) has been ensured.Ensureing gas Under the premise of amount is stablized, produced in conjunction with pumping between implementation, it is ensured that have certain submergence, flowing bottomhole pressure (FBHP) that can also keep steady in pit shaft It is fixed.To be cost-effective to the greatest extent, the difference of time-of-use tariffs is rationally utilized, it is quasi- in next step to take 22:00-8:00 opens pumping, The remaining time stops the working system of well.For not producing the well of liquid, stopping finding time can be appropriately extended.

Implementation result：It is taken out by the gas well intensification pump extension to 8 mouthfuls of low yield liquid, low submergence and between implementing, finds its yield The phenomenon that having no influence, also effectively preventing because submergence is too low, and lead to oil pipe outlet, eliminates Well site safety hidden danger；And And individual well average production time only 10.5 hours, one day 0.5 yuan of average electricity price/degree, 25 degree/day of individual well average consumption, then individual well 1 year 2566 yuan of 13.5 × 25 ÷ of power cost saving, 24 × 0.5 × 365 ≈, specific statistical data is shown in Table 2：

Producing well statistics is taken out between table 2

It is as shown in Fig. 2 wherein to prolong 1-6-8 well production curves.

As can be seen from the above-described embodiment, by carrying out flowing bottomhole pressure (FBHP) and work to the coal bed gas well in the different mining stages The scheme of corresponding dynamic adjustment pump setting depth has been formulated in the analysis for making system, and above carrying pump in height flows kill-job hangs, not only because Reduce the usage amount of tube rod pump and reduce tube rod load, reduces eccentric wear, also add the migration stroke of coal dust, avoid Coal seam section high corrosion, easy fouling environment, reduce gas field production cost, extend gas well is excused from a college course the phase；In low yield liquid, droning do not have Degree well in deepen pump hang, implement between takes out, not only reduce side-abrasion of rod string, saved the electricity charge, also effectively prevent oil pipe outlet this One major safety risks；Dynamic adjustment pump setting depth meets the production needs of coal bed gas well, and effect of field application is good；Plan It, can be because of ground, being applicable of suiting measures to differing conditions in terms of time in production from now on.

Finally it should be noted that：The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, Although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the art, still may be used With technical scheme described in the above embodiments is modified or equivalent replacement of some of the technical features. All within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should be included in the present invention's Within protection domain.

Claims (2)

1. a kind of coal bed gas well dynamic adjustment pump hangs discharge and mining method, which is characterized in that specifically include following steps：

(1) it is directed to high stream kill-job, the time in quantitative forecast hydrodynamic face arrival coal seam is required according to mining system, in pump detection period The well that coal seam position is still not achieved in liquid level above carries on pump extension to coal seam；In each pump detection and workover, according to stream pressure situation adjustment Pump is hung；

(2) by analyzing the creation data acquired by hydrodynamic face, indicator diagram measurement, low yield due to stratum feed flow deficiency is found out The well of liquid, low submergence is deepened pump and is hung, and the suction inlet of pump is uniformly lowered into coal storage layer hereinafter, and being taken out between implementation.

2. a kind of coal bed gas well dynamic adjustment pump according to claim 1 hangs discharge and mining method, which is characterized in that taken out between described Take 22:00-8:00 opens pumping, remaining time stops the working system of well；For not producing the well of liquid, stopping finding time suitably to prolong It is long.