用于计量的天然气压缩因子计算方法比较

第20卷第5期　　　　　　　　　　　　　　　　天　然　气　工　业　　　　　　　　　　　　　　　　集输工程

用于计量的天然气压缩因子计算方法比较

张福元3

(西南油气田公司天然气计量检测中心)

　　张福元. 用于计量的天然气压缩因子计算方法比较. 天然气工业,2000;20(5) :73～76

　　摘　要　天然气压缩因子或超压因子计算结果的准确性直接影响天然气流量计量的准确性。当前国内天然

1〕

气计量界广泛使用A G ANX 219〔,A G A8号报告,ISO 1221321997三种天然气压缩因子计算方法标准。文章研究了这三种天然气压缩因子计算方法标准, 并编写了N GZCWIN 天然气压缩因子计算软件, 通过对不同气样和不同温度、压力条件的计算, 比较了三种计算方法的差别, 并对这些计算方法的应用范围和不确定度提出了看法。　　主题词　天然气　计量　压缩系数　计算　方法　分析

天然气压缩因子计算方法简介

1. A G A8号报告

2〕　　在A G A8号报告1994年版中〔, 提供了以组成程。式(1) 二维维里方程; (2,

只有个别参数有差别。物性测定数据方程有四组数据输入方法, 见表1。

1天然气组成的摩尔分数或摩尔百分数(分析数据) A01A02

, 见表1。

32u

　　Z =1+3-D C n T n +

K n =

13

18

相对密度、高位发热量及二氧化碳、氢气

和一氧化碳的摩尔分数相对密度及氮气、二氧化碳、氢气

和一氧化碳的摩尔分数

ISO 12213方法

∑

n =13

∑C 3T 2

n

58

u n

(b n -c n k n D k n ) D b n e 2c n D

2

k

I00天然气组成的摩尔分数或摩尔百分数(分析数据)

n

(1)

I01I02I03I04

相对密度、高位发热量及二氧化碳

和氢气的摩尔分数

相对密度、高位发热量及氮气和氢气的摩尔分数相对密度及垢氧化碳、氮气和氢气的摩尔分数高位发热量及二氧化碳、氮气和氢气的摩尔分数

NX 219方法

Z =1+B mix d +C mix d (2)

式中:Z 为压缩因子; D 为化简密度; d 为摩尔密度,

mol/L; K 为混合大小参数; B , B mix 为二维维里系

3

数; C n 为同组成数据有关的系数; T 为温度, K; C mix 为三维维里系数; u n 、b n 、c n 、k n 为标准给定的常

数。　　根据压力、温度和天然气数据,A G A8报告可分为管输范围和扩展范围二类, 见表2。物性测定数据方程(A01和A02) 只适用于在管输范围内使用。符合管输范围条件的计算不确定度在0. 1%内。　　2. ISO 12213方法　　同A G A8号报告相似, ISO 12213〔3〕也有组成分析数据和物性测定数据二种方程, 其表达式都相同,

N00天然气组成的摩尔分数或摩尔百分数(分析数据) N01N02N03

相对密度及二氧化碳和氮气的摩尔分数相对密度及二氧化碳、氮气和甲烷的摩尔分数高位发热量及二氧化碳和氮气的摩尔分数

　　根据压力、温度和天然气数据, ISO 12213分为

管输范围和扩展范围二类, 见表2。管输范围天然气数据和物性测定数据计算不确定度估算见图1。

　　3张福元, 高级工程师,1960年生;1982年毕业于福州大学, 现任西南油气田公司天然气计量检测中心总工程师。曾在公开刊物发表过多篇论文。地址:(610213) 四川省成都市华阳。电话:(028) 3347480转231890。

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集输工程　　　　　　　　　　　　　　　天　然　气　工　业　　　　　　　　　　　　　　　　2000年9月

表2　A G A8号报告和ISO 12213的适用范围

项　　目压　力温　度

(MPa )

AGA8号报告

ISO 12213

0～12

0～280-130～4000. 07　

～1. 520～660～1000～1000～1000～1000～120～60～40～露点

0～12-10～650. 55　～0. 8030

～4570～1000～200～200～100～3. 50～1. 50～0. 50～0. 10～0. 050～0. 0～651

) )

　　扩展天然气组成数据在压力为0～10MPa , 温度为-10℃～65℃, 某些组成含量同压缩因子计算不确定度的关系见表3。

表3　ISO 方法计算扩展天然气　　　　　　　组成数据压缩因子的不确定度　　(mol %) 不确定度

0. 1%

0. 2%

0. 5%

(℃) -8～65-48～7710. 55　

～0. 9020～4850～1000～500～300～200～50～1. 50～0. 50～0. 10～0. 050050. 50～100～30～0. 020～0. 02

相对密度0. 554　

～0. 87

高位发热量18. 7　

(MJ/m 3) ～45. 1甲　烷(mol %) 45～100氮　气(mol %) 二氧化碳(mol %) 乙　烷(mol %) 丙　烷(mol %) 丁烷总和(mol %)

0～500～300～100～40～1

输入数据组成物性组成物性组成物性

氮气Φ50Φ20—50%——二氧化碳氮气Φ23Φ9%Φ26Φ12Φ2823%

乙烷Φ13Φ10Φ20Φ11—Φ12%丁烷Φ6%3. 5Φ10Φ4%—4. 5%

戊烷总和(mol %) 0～0. 3

C 6+/已烷(mol %) 0～0. 2

庚　烷(mol %)

C 8+

(mol %)

0～0～30～10～210～露点0～100

　　3. NX 219方程　　根据计算压力和温度调整系数使用的数据不同NX 219二类,NX 219。(0. 75, 二氧化碳15%, 不含重烃和其他惰性气体。

　　(2) 压力不大于34. 5MPa 。　　(3) 温度为-40～115℃。　　(4) 不确定度一般为0. 5%。

氦　气(mol %) 0～0. 2氢　气(mol %) 一氧化碳(mol %) 氩　气(mol %) 氧　气(mol %)

00～300

00. 0～100～30～0. 020～0. 020～0. 0150～0. 02

计算方法比较

　　为了比较方便, 本文采用A G A8号报告和ISO

4,5〕3

12213标准中的检查样品和有关文献〔的实验数据作为比较样品, 用N GZCWIN 软件计算压缩因子。天然气组成数据见表4。　　1. 检查样品　　表5列出表1中三种计算方法标准, 共12种数据输入方法计算表4中5个A G A8号报告检查样品对应标准检查值的平均相对偏差。从表4的数据可见,A G A8号报告5个检查样品都为管输范围(表2) 的天然气。　　从表5中的数据可见, 在组成数据和物性数据方法中,A G A8号报告和ISO 12213二种方法标准对应的计算结果没有差别; 组成数据方法的相对偏差小于0. 005%, 物性数据方法的相对偏差也小于0. 05%; 对于NX 219标准, 组成数据方法偏差、物性数据方法偏差分别小于0. 3%和0. 5%。

水(蒸气) (mol %) 0～0. 05硫化氢　(mol %) 0～0. 02

0～0. 0150～0. 02

　　　注:1) 用天然气物性数据时, 压力和温度分别为:0～12

MPa 和-10～65℃。

图1　ISO 12213方法压缩因子计算不确定度估算

　　3技术报告, 天然气压缩因子计算方法验证研究, 四川石油管理局天然气研究院,1996年。

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第20卷第5期　　　　　　　　　　　　　　　　天　然　气　工　业　　　　　　　　　　　　　　　　集输工程

表4　天然气样品组成数据

名称

A G A821A G A822A G A823A G A824A G A825ISO 21ISO 22ISO 23

ISO 241

)

N 20. 263. 131. 015. 700. 303. 101. 005. 700. 280. 640. 250. 561. 293. 224. 160. 100. 072. CO 20. 600. 471. 507. 590. 600. 501. 507. 600. 390. 430. 600. 521. 110. 422. 961. 411. 5207

C 196. 5290. 6785. 9181. 4481. 2196. 5090. 7085. 9073. 5081. 2082. 6098. 0097. 0796. 5094. 5391. 0890. 6684. 8981. 2790. 6068. 16

C 21. 824. 538. 493. 304. 301. 804. 508. 503. 304. 303. 501. 280. 981. 750. 963. 464. 594. 200. 202. 604. 94

C 30. 460. 832. 300. 610. 900. 450. 842. 300. 740. 900. 750. 450. 401. 551. 760. 782. 030. 56944. 5. 6. 49

i C 4n C 4i C 5n C 5C 60. 070. 04

C 7C 8O 2H 2

0. 100. 100. 350. 100. 150. 100. 100. 350. 120. 150. 120. 080. 100. 300. 500. 100. 53942. 231. 21

0. 100. 160. 350. 100. 150. 100. 150. 350. 120. 150. 120. 180. 100. 790. 550. 140. 800. 2. 812. 893. 84

0. 050. 030. 05

0. 030. 040. 05

13. 470. 99

0. 050. 030. 050. 040. 040. 070. 100. 220. 08030. 582. 080. 640. 87

0. 030. 040. 050. 040. 040. 100. 100. 190. 1702260. 090. 431. 750. 540. 34

0. 070. 040. 020. 02

0. 010. 01

0. 03

0. 100. 24

0. 0. 132. 620. 540. 24

0. 112. 838. 720. 130. 090. 14

0. 02

0. 01

9. 50

10. 001. 6011. 701. 10

ISO 25ISO 26N G 01N G 02N G 03N G 04N G 05N G 06

2)

N G 07N G 08N G 09N G 10N G 11N G 12N G 13

6. 7210. 53

1. 3810. 54

3. 9. 6012. 800. 80

　　　　　　注:1) 含1. 00%的CO ; 2) 含0. 01%的H 2O 。

)

表5　A G A8号报告检查例样计算结果1

相　对　偏　差2) ()

计算方法

A G A821A G A822A G A823A G A824A G A825

A00A01A02I00I01I02I03I04N00N01N02N03

0. 000. 000. 000. 000. 010. 010. 010. 010. 050. 010. 04-0. 30

0. 000. 020. 020. 000. 030. 030. 030. 020. 080. 160. 07-0. 21

0. 000. 030. 030. 000. 040. 040. 040. 040. 280. 480. 300. 01

0. 000. 020. 020. 000. 020. 020. 030. 02-0. 060. 00-0. 08-0. 27

0. 000. 040. 040. 000. 040. 040. 050. 04-0. 020. 06-0. 05-0. 27

品对应标准检查值的平均相对偏差。从表4的数据可见, ISO 12213标准中6个检查样品都为管输范围(表2) 的天然气。

表6　ISO 12213标准检查例样计算结果比较1)

A00A01A02I00I01I02I03I04N00N01N02N03

ISO 210. 00-0. 020. 020. 000. 00-0. 010. 01-0. 030. 240. 240. 19

相　对　偏　差2) () ISO 22ISO 23ISO 24ISO 25

0. 000. 030. 030. 000. 030. 030. 030. 030. 260. 030. 03

0. 000. 000. 000. 000. 000. 000. 000. 000. 010. 010. 010. 00

0. 00-0. 07-0. 060. 00-0. 08-0. 08-0. 10-0. 330. 16-1. 56

0. 000. 080. 120. 000. 080. 090. 120. 060. 11

ISO 260. 00-0. 05-0. 040. 00-0. 05-0. 05-0. 03-0. 060. 11

　注:1) 压力范围:0. 102～8. 274MPa , 温度范围:273. 15～

327. 59K , 计算点数:32; 2) 相对偏差=(计算值-A GA8检查

-0. 14-0. 02

值) /A GA8检查值×100%。

-4. 42-0. 19-0. 07-1. 88-0. 80-0. 65

-0. 71-0. 49

　　表6列出表1中三种计算方法标准, 共12种数据输入方法计算表4中6个ISO 12213标准检查样

注:1) 压力范围:6～12MPa , 温度范围:273.15～333. 15K , 计算点　

数:10; 2) 相对偏差=(计算值-ISO 12213检查值) /ISO

12213检查值×100%。

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集输工程　　　　　　　　　　　　　　　天　然　气　工　业　　　　　　　　　　　　　　　　2000年9月　　从表6可见, 三种计算方法标准的总体结果同表5, 不同之处在于物性数据方法。ISO 24样品由于含氢气(9. 5%) 和高压(12MPa ) , 使得I04的相对偏差达到-0. 3%,NX 219的N01、N02和N03分别为-1. 56%、-4. 42%和-1. 88%; ISO 25样品由于高含二氧化碳(7. 6%) 和高压(12MPa ) , 使得A02和I03的相对偏差达到0. 12%, NX 219的N03为-0. 80%。

　　从表7可见,A00和I00的计算结果一致; 对于管输范围天然气, 三种计算方法标准的计算误差平均在0. 1%以下,A00和I00最大为-0. 14%, N00为-0. 25%。对于含重烃天然气,A00和I00表现也很好, 最大误差为-1. 05%, 在高的压力下(超出适用范围) , 不能采用NX 219计算压缩因子。

结束语

　　在A G A8号报告和ISO 12213的标准起草过程中, 已经对计算方法的不确定度进行详细的研究, 并给出了不确定度的估算方法; 在NX 219标准中, 没有提供估算不确定度的资料。为了比较三种计算方法标准的异同, 提出以下建议。

　　(1) 目前国内管输天然气气质、输送压力和温度, 在10MPa 内用A G A8、ISO 　　2. 压力温度影响

　　三种计算方法标准的适用范围各不一样, 为了进一步比较它们的差别, 本文用表4中的ISO 26号样品, 在压力为0～280MPa 范围内, 温度为-50℃、20℃和90℃下计算A00、A01、I00、I01和N00五种方法的压缩因子, 计算结果表明三种温度和全压力范围I00方法的计算结果同A00方法一致,A01和I01的计算结果基本相同, 这同上面的结果一致。对

于A01和I01方法, 在-50℃下的计算结果偏差较大, 至约16MPa 时, 方程无解; 在约18MPa 压力下,20℃和90℃的偏差都在-1%以内有解压力约为40MPa , 而70MPa 。对于, MPa 下, 三

0. 0. 5%。

, 只要在标, 其计算结果均有效。

(2) 对于高压或低温或在管输质量外天然气的压缩因子计算, 如天然气勘探和开发, 需要准确计算时, 宜使用A G A8号报告或ISO 12213标准中的组成数据方法, 计算的不确定度一般都能满足要求。　　(3) 标准中的物性数据方法是为方便在现场配备在线物性参数测定仪器而增设的简便方法, 计算精度不如组成数据方法。我国天然气数据大多用气相色谱仪分析, 故宜采用组成分析方法。

参　考　文　献

1　A G A , Manual for the determination of supercompressibility

factors for natural gas ,Dec. ,1962

2　A G A Transmission measurement committee report No. 8,

compressibility factors of natural gas and other related hy 2drocarbon gases ,2nd Printing ,J uly ,1994

3　ISO 12213-1997(E ) ,Natural gas —calculation of compres 2sion Factor

4　Eclingto R T etc. , G as Proc. Ass. ,Fifth Annual Convention ,

P193

5　Qun Li and Tian -min Guo ,J. Pet. Sci. Eng. ,1991; (6) :

235

(收稿日期　2000-03-05　编辑　王瑞兰)

%。

　　3. 文献样品　　为进一步比较三种计算方法标准计算压缩因子的结果, 用三种计算方法标准中的组成分析数据方法计算表4中13个天然气样品的压缩因子, 其平均误差见表7。

表7　天然气样品计算结果比较1)

天然气

N G01

N G02N G03N G04N G05N G06N G07N G08N G09N G10N G11N G12计算点数

[***********]3不确定度2) ()

ISO

(MPa ) (℃) AGA8NX 219

12213

0. 72～7. 1137. 05-0. 14-0. 14-0. 251. 00～6. 0032. 5～600. 090. 090. 001. 13～5. 2626. 7-0. 04-0. 04-0. 030. 74～7. 1138. 45-0. 11-0. 110. 001. 00～7. 0030～800. 130. 130. 131. 13～6. 3015. 56～26. 7-0. 01-0. 010. 031. 00～6. 00400. 100. 100. 060. 66～7. 5338. 75～86. 250. 010. 01-0. 1678. 49～94. 135. 55-0. 89-0. 90-61. 0036. 96～84. 135. 05-1. 05-1. 0523. 8929. 63～45. 133. 35-1. 00-1. 001. 410.

75～7. 3239. 25～86. 25-0. 20-0. 200. 19压力范围

温度范围

　注:1) N G01～N G08为管输天然气,N G09～N G13为含重烃天然

气; 2) 不确定度=(计算值-实验值) /实验值×100%。

　

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……………………

72,9/25/2000. (ISSN 1000-0976; In Chinese)

ABSTRACT:The distribution of the low 2permeability gas

LAMINAR FLOW STABI L IT Y REGIME

THEOR Y FLOW

reservoirs in China is very wide and their reserves amount to 80%of the reserves of the total gas reservoirs in China according to an incomplete statistics. Obviously ,developing this kind of gas reservoirs is of an important practical significance , but up to now ,the low 2permeability data have been interpreted by adopt 2ing the conventional gas reservoir theory in general and the ideal results have not been obtained often due to the particularities the low 2permeability gas reservoirs have but the conventional ones have not ,such as tight rocks ,extremely low permeability and gas percolation flow with slippage effect ,etc. In view of this situa 2tion ,a corresponding mathematical model is set up on the basis of investigating and studying a vast amount of the foreign and do 2mestic literatures and the practical calculation and starting from studying the specific property of the flow in low 2permeability of the coeffi 2and in the equa 2equation which solution is acquired iteration method is obtained. The model and the calculation method in the paper can be fit in better with the mea 2sured data of the gas well through processing the data of one well in central Sichuan. As a result of this work ,an effective method for solving this kind of problems is found out and this achieve 2ment is easy to be spread to the multidimension and multiphase model.

SUB JECT HEADING S :Low 2permeability pools , Reservoir rock , G as field development , Slippage , Mathematical model , Sichuan basin

Li Tiejun (associate prof essor ) , born in 1964,graduated in mathematics from Sichuan University in 1985and received his Master ′s degree in oil and gas field development in 1996. Now he is engaged in teaching work and the researching work on numer 2ical simulation. Add :Department of Computer Science , S outh 2west Petroleum Institute ,Nanchong ,Sichuan (637001) ,China 　

FOR DISTINGUISHING L IQUID

　　He Shiming (Southwest Petroleum INstitute ) , Luo Deming (Southwest Petroleum G eology Bureau ) , Yu Haisheng (Huabei Petroleum Administration ) and Liu Chongjian (Southwest Petroleum Institute ) .

N A TU R. GA S IN D. v. 20,no. 5,pp. 67～69,9/25/

2000. (ISSN 1000-0976; In Chinese)

ABSTRACT:Accurately distinguishing the flow regime of the liquid in well is very important for optimizing drilling design and operation and guaranteeing cement replacement quality. In this paper , the common five criteria for distinguishing flow regime —Reynolds number (Re ) and stability parameters (Z ) , (K ) , (X ) and (Y ) , are presented on the basis of the laminar

flow stability theory. Through analysis and comparison of five criteria for distinguishing flow regime is the Roynolds number and K unperfect ,but the Y relatively ra 2tional. The authors the stability parameters X and Y , enabling them to be used for distinguishing the flow regime of the circular pipe flow ,concentric annular flow and ec 2centric annular flow of other non 2Newtonian liquids.

SUB JECT HEADING S :Fluid , Laminar flow , Stability , Reynolds number ,Annulus flow ,Drilling

H e Shiming (lecturer ) , born in 1966,graduated in drilling engineering from the S outhwest Petroleum Institute in 1988and received his Master ′s degree in 1991and Doctor ′s degree in petroleum engineering in 1998. Now he is engaged in the teach 2ing and researching works on drilling engineering ,annulus fluid mechanics and borehole temperature field. Add :Department of Petroleum Engineering of S outhwest Petroleum Institute , Nan 2chong ,Sichuan (637001) ,China 　　Tel :(0817) 2642936

　Tel :(0817) 2643345

……………………

……………………

A STU DY OF THE MATHEMATICAL MOD 2E L

OF

G AS

PERCOLATION

FLOW

THR OUGH LOW 2PERMEABI L IT Y RESER 2V OIR AN D ITS CALCU LATION METH OD

　　Li Tiejun and Li Yun (Southwest Petroleum In 2stitute ) . N A TU R. GA S IN D. v. 20, no. 5,pp. 70～9

A COMPARISON OF THE METH ODS FOR CALCU LATING NATURAL

G AS DEVIA 2

TION FACT ORS USED FOR METERING

　　Zhang Fuyuan (Natural G as Metering and Detec 2tion Center of Southwest Oil and G as Field Branch ) .

N A TU R. GA S IN D. v. 20,no. 5,pp. 73～76,9/25/

2000. (ISSN 1000-0976; In Chinese)

ABSTRACT :The accuracy of the results in calculating nat 2ural gas deviation factors or supercompressibility factors directly affects the metering accuracy of gas flow rate. At present ,the do 2mestic natural oil and gas metering circles widely use three crite 2ria for calculating natural gas deviation factors ,i. e. A G ANX 219and A G A 8reports and ISO 1221321997. In this paper ,the three criteria for calculating natural gas deviation factors are studied , the N GZCWIN software for calculating natural gas deviation fac 2tors is compiled ,the differnece among the three calculation meth 2ods is compared through calculating different gas samples at dif 2ferent temperature and pressure and some opinions on the appli 2cation scale and indeterminateness of these calculating methods are put forward.

SUB JECT HEADING S :Natural gas , G auging , Compress 2ibility coefficient ,Calculation ,Method ,Analysis

Zhang Fuyu an (senior engineer ) , born in 1960,graduated from Fuzhou University in 1982. Now he is chief engineer of Natural G as Metering and Detection Center , S outhwest Oil G as Field Branch. He has published many theses 2cations. Add :Huayang ,Chengdu Tel :(028) 3347480neering for tubing.

SUB JECT HEADING S :Sichuan gas field ,East , Tubing cor 2rosion , Hydrogen sulfide corrosion , Carbon dioxide corrosion , Feature ,Principle ,Analysis

Liu H uixin (associate prof essor ) , born in 1954,graduated from S outhwest Petroleum Institute in 1977and received his Master ′s degree in engineering in 1988. He is mainly engaged in the teaching and researching works on petroleum engineering. Add :S outhwest

Petroleum

Institute , Nanchong , Sichuan

(637000) ,China 　　Tel :(0817) 2643920

……………………

PR OGRESS IN DIMETH YL ETHER SY N 2THESIS METH OD

Y and Department of Oil Engineering ,

Sichuan

) and Cao Yu (Research In 2of Natural G as ,SPA ) . N A TU R. GA S IN D. v. 20,no. 5, pp. 79～83, 9/25/2000. (ISSN 1000-0976; In Chinese)

……………………

ABSTRACT :As an important raw material for chemical in 2dustry and clean fuel ,the dimethyl ether (DME ) synthesis tech 2nique by one 2step method has rapidly developed in recent years. As compared with two 2step method ,the production cost of DME by one 2step method is low ,which lays a foundation for extending its application scope. This paper expounds that the thermody 2namic advantages of DME synthesized by one 2step method as compared with that by two 2step method stem from the coordi 2nate effect engendered due to the many chemical reactions oc 2curred at the same time. The thermodynamic advantages directly lead to raise of the synthetic gas convension rate. In this paper , the developing situation of two DME synthesis techniques by one 2step method (slurry bed and fixed bed synthesis techniques ) is summarized ,the progress in these two techniques represented by N KK and Haldor Tops

SUB JECT

HEADING S :Dimenthyl

ether , Synthetic ,

TECHNIQUE B Y ONE 2STEP

ESSENTIAL FEATURES OF TUBING COR 2R OSION PHEN OMENA IN CHUAN DONG G AS FIE LD

　　Liu Huixin (Southwest Petroleum Institute ) and Su Y ongping (Chuandong Development Company ) .

N A TU R. GA S IN D. v. 20,no. 5,pp. 77～79,9/25/

2000. (ISSN 1000-0976; In Chinese)

ABSTRACT :The problem of tubing corrosion is very out 2standing in exploiting the oil and gas containing sour gas corro 2sive medium (H 2S and CO 2,etc. ) in Chuandong gas field. Be 2cause the surroundings in which the downhole tubing is placed are very complex and there are many corrosive factors ,the corro 2sion phenomena are various and too numerous to enumerate. Summarizing the variation law of tubing corrosion occurrence and development from various corrosion phenomena is a key link for solving the problem of tubing corrosion. In this paper , through summing up and sorting out the practical data from worksite and combining with mechanism analysis ,the essential features of the tubing corrosion phenomena in Chuandong gas field are expound 2ed ,providing a reliable basis for guiding the anticorrosion engi 2

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