CN103375164B

CN103375164B - Method for judging frozen plugging position of pipeline

Info

Publication number: CN103375164B
Application number: CN201210109389.4A
Authority: CN
Inventors: 韩兴刚; 王晓荣; 王惠; 王宪文; 冯朋鑫; 徐文龙; 卢文伟; 梁凌云; 刘静
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2012-04-13
Filing date: 2012-04-13
Publication date: 2016-07-13
Anticipated expiration: 2032-04-13
Also published as: CN103375164A

Abstract

The invention discloses a method for judging a frozen and blocked position of a pipeline and gas partial pressure skid-mounted equipment used by the method, which are designed for accurately judging the frozen and blocked position of the pipeline. The method comprises the steps of injecting high-pressure gas in a pressure division tank in the skid-mounted equipment into a pipeline or shunting the gas in the pipeline into the pressure division tank, recording pressure and temperature change values before and after gas injection, and determining the frozen and blocked position of the pipeline through formula calculation. The technical principle is reliable, and the required parameters can be directly obtained by using a metering instrument. The skid-mounted equipment can realize vehicle-mounted mobile operation, compared with the prior art, the technology does not need to excavate pipelines, and has the characteristics of simple and convenient operation, time and labor saving and more accurate result.

Description

The determination methods of pipeline frozen block position

Technical field

The present invention relates to determination methods and the partial pressure skid mounted equipment of use thereof of a kind of pipeline frozen block position, belong to gas Development technique field, field.

Background technology

During the construction of natural gas fields, owing to gas existing condensed liquid and water, when ambient temperature is too low, these liquid and The water person of being easy to forms hydrate or icing, by line clogging, affects gas well and normally produces.At present, although pipeline method for removing blockage Numerous, but there is no the effective method accurately judging pipeline frozen block position, it is usually by empirical discriminant method or uses two way classification.Warp The method of testing is according at pipeline low lying areas, pipeline reducing and the position such as valve is susceptible to the position of blocking and judges with experience Pipeline frozen block position；Two way classification is to utilize two points of segmentation methods to judge roughly pipeline blocking position, then need repeatedly to excavate pipeline, Waste time and energy, it is judged that error is relatively large.

Summary of the invention

It is an object of the invention to provide determination methods and the partial pressure skid of use thereof of a kind of pipeline frozen block position Equipment, its by from dividing potential drop tank to pipeline inject gases at high pressure or separate from pipeline gas in dividing potential drop tank until pressure is put down Weighing apparatus, goes out the length of blocking pipeline, accurately determines blocking position according to the change calculations of gas pressure and temperature.The present invention's is concrete Technical scheme is as follows:

Partial pressure skid mounted equipment: being connected by dividing potential drop tank, gas injection pipeline and metering device and form, dividing potential drop tank is to have receiving one The gas tank of constant-pressure, gas injection pipeline is the center-aisle connecting dividing potential drop tank with surface line, and metering device is by high-precision pressure Meter and thermometer form.

The computational methods of pipeline frozen block position:

Determine pipeline blocking after, skid mounted equipment is connected with gathering line, inject in gathering line from pressure be P₂、 Volume is Qm³A part of gas of dividing potential drop tank, or from gathering line inward pressure P₂, volume be Qm³Dividing potential drop tank in shunting A part of gas, pressure reaches balance.Before assuming gas injection or shunting before gathering line pressure be P₁, collector and delivery pipe after gas injection or shunting Line pressure becomes P₃, pipeline diameter is Dmm, seeks frozen block depot siding length l？.

Obtained by the equation of gas state:

Gathering line pressure P₁, then: P₁V=n₁ZRT₁,

Skid mounted equipment gas pressure P before gas injection or shunting₂, then have: P₂Q=n₂ZRT, then

After gas injection or shunting balance, pressure is P₃, then have: P₃(V+Q)=n₃ZRT₃, then

Wherein, according to mass conservation law, then have: n₁+n₂=n₃

Simultaneous aforesaid equation:

V = \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}} \times Q

After volume is obtained, pipeline diameter D is it is known that be then easy for showing that frozen block depot siding length l is:

l = \frac{4 Q}{{πD}^{2}} \times \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}}

Ground injecting gas or shunt gas that the present invention proposes determine that pipeline choked technique is by dividing potential drop tank in skid mounted equipment In gases at high pressure are injected into pipeline or by gas distribution in pipeline to dividing potential drop tank, enroll pressure, variations in temperature before and after gas injection Value, is calculated by formula and determines pipeline frozen block position.This know-why is reliable, and it is straight that required parameter all may utilize measuring instrument Obtain.Skid-mounted type equipment can realize vehicle-mounted floating operation, and compared with the conventional method, this technology, without excavating pipeline, has Easy and simple to handle, the time saving and energy saving and the most accurate feature of result.

Accompanying drawing explanation

Fig. 1 is the schematic diagram being injected in gathering line by skid mounted equipment mesohigh gas.

Fig. 2 is by the schematic diagram in gas distribution in gathering line to skid mounted equipment.

Detailed description of the invention

With reference to Fig. 1 and 2, embodiments of the invention are further illustrated:

Embodiment 1:

Partial pressure skid mounted equipment: connected by dividing potential drop tank 1, gas injection pipeline 2 and metering device 3 and form.

After determining pipeline blocking, skid mounted equipment is connected with gathering line, is 1m from pressure 0.1MPa, volume³Dividing potential drop Tank injects a part of gas (as shown in Figure 1) in gathering line, and pressure reaches balance, and temperature keeps constant.Before assuming gas injection Gathering line pressure 2.5MPa, after gas injection, pressure becomes 3.3MPa, and pipeline diameter is 50mm, seeks frozen block depot siding length l？.

According to computing formula:

l = \frac{4 Q}{{πD}^{2}} \times \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}} = 3000 m

Embodiment 2:

After determining pipeline blocking, skid mounted equipment is connected with gathering line, from gathering line inward pressure 0.1MPa, volume For 1m³Dividing potential drop tank in shunt a part of gas (as shown in Figure 2), pressure reach balance, temperature keep constant.Before assuming gas injection Pressure is 2.5MPa, and after shunting, pressure becomes 2.15MPa, and pipeline diameter is 50mm, seeks frozen block depot siding length l？

According to computing formula:

l = \frac{4 Q}{{πD}^{2}} \times \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}} = 3000 m .

Claims

1. the determination methods of a pipeline frozen block position, it is characterised in that:

After determining pipeline blocking, being connected with gathering line (4) by skid mounted equipment, in gathering line (4), injection from pressure is P₂, volume be Qm³A part of gas of dividing potential drop tank (1), or from gathering line (4) inward pressure P₂, volume be Qm³Point Shunting a part of gas in pressure tank (1), pressure reaches balance；Before assuming gas injection or shunting before gathering line (4) pressure be P₁, note After gas or shunting, gathering line (4) pressure becomes P₃, pipeline diameter is Dmm, seeks frozen block depot siding length l；

Obtained by the equation of gas state:

Gathering line pressure P₁, then: P₁V=n₁ZRT₁,

Wherein, according to mass conservation law, then have: n₁+n₂=n₃

Simultaneous aforesaid equation:

V = \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}} \times Q

l = \frac{4 Q}{{πD}^{2}} \times \frac{P_{3} T_{1} T_{2} - P_{2} T_{1} T_{3}}{P_{1} T_{2} T_{3} - P_{3} T_{1} T_{2}} .