1、API PUBL*4589 93 m 0732290 0517489 9Lb m Fugitive Hydrocarbon Emissions from Oil and Gas Production Operations HEiALTH AND ENVIRONMENTAL SCIENCES API PUBLICATION NUMBER 4589 DEXEMBER 1993 Environmental Purtnership American Petroleum Institute 1220 L Street. Northwest Washington, D.C. 20005 11 API PU
2、BL*4589 33 0732290 0537490 638 W Fugitive Hydrocarbon Emissions from Oil and Gas Production Operations Health and Environmental Sciences Department PUBLICATION NUMBER 4589 PREPARED UNDER CONTRACT BY: STAR ENVIRONMENTAL P.O. BOX 13425 TORRANCE, CA 90503 DECEMBER 1993 American Petroleum Institute API
3、PUBL*45B9 93 0732290 0.537493 574 m FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYERS, MANUFAC- TURERS, OR SUP
4、PLIERS To WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY RISKS AND PRECAUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATIO
5、N OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCT COV- ERED BY LETTERS PATENT. NEITHER SHOULD ANYTHING CONTAINED IN ITY FOR INFRINGEMENT OF LETERS PATENT. THE PUBLICATION BE CONSTRUED AS INSURING ANYONE AGAINST LIABIL- Copyright O 1993 American Petroleum Instit
6、ute II API PUBLX4589 93 0732290 0537472 400 m ACKNOWLEDGMENTS THE FOLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS OF TIME AND EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT MI STAFF CONTACT(sL Dr. Paul Martino, Health and Environmental Sciences Department MEMBERS OF THE FU
7、GITIVE EMISSIONS PROJECT GROUP John Bourke, ARCO Oil and Gas Company Kerry Mire, Texaco E 2. Development of emission factors; 3. Development of profiles of speciated hydrocarbon emissions including air toxics; 4. Assessment of regional differences in fugitive emissions; and, 5. Assessment of control
8、 efficiency of Inspection and Maintenance programs. STUDY GUIDELINES AND PROCEDURES The following types of petroleum production facilities were visited: Onshore light crude production Onshore heavy crude production Onshore natural gas production Onshore natural gas processing plants Gulf of Mexico o
9、ffshore platforms At the beginning of each site visit, monitoring personnel met with representatives of the operating company to become oriented with the facility lay-out and safety requirements. Monitoring and sample collection activities started immediately after the orientation meetings. The foll
10、owing precautions were ES-1 taken to assure that monitoring data and hydrocarbon samples were representative of the normal operating condition of each facility: Monitoring work was conducted without petroleum company supervision; Coimponents that gave elevated screening values were recorded on confi
11、dential field data sheets (these were not shown to oil company personnel until the end of the visit); No identification markers were attached to emitting components during the time between screening and hydrocarbon collection; Collection of fugitive hydrocarbon emission samples occurred as soon afte
12、r detection as possible to minimize the possibility of changes due to maintenance activities. During the first days of each visit, all components were counted, logged, and screened with portable hydrocarbon monitoring instruments equipped with flame ionization detectors. All elevated readings (1 O p
13、arts-per-millicm by volume, methane equivalence ppmv or more) were recorded; descriptive information about each component that gave an elevated reading was also recorded. NOTE: Components with lSVs of 10 ppmv or more are referred to in this report as “emitters.” Approximately 15 percent of the emitt
14、ers were enclosed in polyethylene tents to collect samples of the fugitive hydrocarbons. NOTE: This procedure is referred to herein as “bagging”. All of the collected samples were speciated into C1 through C6+ fractions. Approximately 25 percent of the samples were also analyzed for air toxics. Mass
15、 emission rates were calculated for all the bagged emitters. Table ES-1 shows the number of components screened, the number of emitters found, and the number of samples collected at each of the five types of petroleum production facilities. The table also shows the number of samples speciated into C
16、1 through C6+ fractions, and the number analyzed for aromatic air toxics. Table ES-1. NUMBER OF COMPONENTS SCREENED, EMITTERS FOUND, AND SAMPLES COLLECTED AND ANALYZED FOR THE APVGRI STUDY I FACILITY I COMPONENTS I EMITTERS I EMITTERS I ANALYZED I ANALYZED I SCREENED FOUND* SAMPLED Cl -C6+ Air Toxic
17、s 48 , 652 99 1 165 165 43 13,756 62 30 30 4 40,178 1,513 92 92 43 35,764 1,615 1 75 1 75 40 45,685 61 5 243 243 38 TOTAL 184,035 4,796 705 705 168- *NOTE: Emitter = ISV 21 O ppmv ES-2 API PUBL*4589 93 m 0732290 0517503 OLb m During the inventory task, components were grouped as follows: 1. Connecti
18、ons (CN) 2. Valves (VL) 3. Open Ended Lines (OEL) 4. Compressor Seals (CS) 5. Pump Seals (PS) 6. Pressure Relief Valves (PRV) 7. Dump Lever Arms (DM) 8. Polished Rod Pumps (ROD) 9. Miscellaneous (MISC) During data analysis, component types 4 through 9 were combined into a single “Others“ category. C
19、orrelation equations were developed from speciation data to show the relationship between lSVs and mass emission rates. A separate correlation equation was sought for each of four component types (CN, VL, OEL, Other) at each of the five types of facility, however, several of the sub-sets of data wer
20、e found to be statistically identical and were therefore combined by type of facility. “Default zero“ emission rates were defined for components with lSVs below 1 O ppmv. Emission factors were developed using the correlation equations and all 184,035 ISVs. This was done by calculating an emission ra
21、te for each ISV using the appropriate correlation equation, then adding all calculated emission rates for each facility type/component type combination to give the total expected emission rates. “Average“ emission factors (average emissions per installed components) were derived by dividing total em
22、issions by the total number of components. “LeaWNo Leak“ and “Stratified“ emission factors were developed by grouping the data according to ISVs. Speciated weight fractions (Cl through C6+, and air toxics) of fugitive emission were also developed. RESULTS Correlation equations were developed for all
23、 five types of petroleum production facilities; emission factors were developed for four of the five types of facilities. Additional data are being collected for gas plants after which those emission factors will be calculated and presented in a separate report. Statistical evaluation showed that be
24、cause many of the correlation equations were statistically equivalent; only eight equations were needed to predict emissions from the five types of facilities. ES-3 API PUBL*4589 93 0732290 0517504 T52 m Emission factors were developed for the same categories as the correlation equations (except gas
25、 processing plants). Speciation factors were developed for each site type. The five types of facilities were defined as follows: ( (usually less than one percent of the total installed components). This suggests that an inspection and maintenance program that can reduce the number of large leaks may
26、 be effective in reducing total fugitive hydrocarbon emissions. Correlation EqlJatiOnS Correlations between lSVs and mass emission rates were calculated from laboratory analyses for lSVs above 1 O ppmv. Correlation equations were developed by regressing the natural logarithm of total hydrocarbon elm
27、issions (ln THC) on the natural logarithm of the instrument screening values (ln ISV). A simple linear regression (least squares fit) was then calculated and converted from log space to arithmetic space using a scale bias correction factor. Table ES-2 gives the correlation equations for all types of
28、 sites. ES-4 API PUBLm4589 93 m 0732290 0537505 999 m Table ES-2. CORRELATION EQUATIONS FACILITY COMPONENT TYPE - - - - CORRELATION EQUATION Onshore Light Crude CN, VL, OEL THC(lb/day) = 8.61 x 1 O-5(lSV pprn). Onshore Light Crude Other THC( Ib/day) = 1.24 x 1 ISV pprnv)0.61 Onshore Heavy Crude All
29、THC( Ib/day) = 3.29 x 1 O-5( ISV pprnv)0.89 Onshore Gas Production CN, OEL THC( Ib/day) = 8.04 x 1 O-6( ISV pprnv) .o2 Onshore Gas Production VL, Other THC(lb/day) = 9.79 x 10-5(lSV pprn)- Onshore Gas Plant All THC( Ib/day) = 1.79 x 1 O-4( ISV pprn)0.8 Offshore Oil Table ES-5 gives component specifi
30、c average THC emission factors for each facility typekomponent type combination. ES-5 API PUBL*4589 93 m 0732290 0537506 825 m Table ES-4. AVERAGE THC EMISSION FACTORS (Overall) All All 0.0085 Ib/day-component 0.0055 Ib/day-component All 0.0233 Ib/day-component All 0.0002 Ib/day-component Table ES-5
31、 AVERAGE THC EMISSION FACTORS (Component specific) rlb/dav-comDonentl CONNECTIONS OTHERS OPEN-ENDED VALVES 0.0041 O. 1 036 0.0099 0.021 7 0.0006 0.2870 0.01 07 0.1 063 0.0038 Onshore Gas Production 0.0007 0.001 o 0.0002 0.0001 0.0991 0.0351 0.01 97 I eak/No Leak Emission Facm Another methold of calc
32、ulating fugitive hydrocarbon emissions is to screen components and determine the number above and below a leak definition (in ppmv). “LeaWNo Leak“ THC emission factors are given in Table ES-6. Table ES-6. “LEAUNO-LEAK THC EMISSION FACTORS (PounddDay-Component) 1 FACILITY I COMP. I No Leak Leak I TYP
33、E 4 0,000 pprnv 10,000 pprnv TYPE CN, VL, OEL 0.00060 - 0.91 Other 2.22 0.00267 VL, Other 0.1 83 0.00012 CN, OEL 2.45 0.00546 VL, Other 0.380 0.00021 CN, OEL 0.1 19 0.00016 All 0.878 0.01 660 Stratified Emission Fact= Stratified THC lemission factors given in Table ES-7 show the emission rates for c
34、omponents with lSVs below 1 O ppmv; from 1 O to 9,999 ppmv; from 10,000 to 99,999; and equal to or greater than 100,000 ppmv. ES-6 API PUBL*45B9 93 m 0732290 0537507 761 m Table ES-7. “STRATIFIED“ THC EMISSION FACTORS Pounds/Da -Com onent Speciated Hydrocarbon Factors Tables ES-2 through ES-7 presen
35、t correlation equations and emission factors for calculating THC (all hydrocarbon species combined). Emission rates for individual hydrocarbon species can be calculated by multiplying THC emissions by the weight fractions given in Table ES-8. I METHANE I Onshore I 0.613 Light Crude I Onshore I 0.942
36、 Heavy Crude I Onshore Gas I 0.920 Table ES-8 SPECIATED FUGITIVE EMISSION FACTORS Neight Fraction of THC emissions in each category) I I I I i ETHYL- I 1 NMHC XYLENES BENZENE TOLUENE BENZENE C6+ VOC 0.387 0.00036 0.00017 0.00075 0.00027 0.02430 0.292 0.058 0.00027 0.00016 0.00089 0.00133 0.00673 0.1
37、 10 0.21 O 0.00010 0.00002 0.00039 0.00023 0.00338 0.035 0.080 0.00372 0.00051 0.00344 0.00935 0.00752 0.030 NOTES: l. Emission factor = Speciated Ernissionsflotal Emissions 2. NMHC = Non-methane hydrocarbon 3. VOC = Propane and heavier hydrocarbon 4. Many hydrocarbons are included in more than one
38、group, for example, C6+ is also included in the NMHC and VOC groups. SUMMARY/CONCLUSIONS Accuracv of Screenina and Bwina Techniques Instrument screening values are influenced by such things as wind speed and direction, instrument dynamics (calibration, battery charge, flow rate), and sampling protoc
39、ols. As a result, there is a wide ES-7 API PUBLa4589 93 m 0732270 0517508 bT8 m variation in IS/s found for each mass emission rate. Statistical analysis of the relationship between lSVs and mas:; emission rates yields a “regression correlation coefficient“ (r) which indicates how closely the two va
40、riables are related. A coefficient of 1 .O0 indicates perfect correlation. Regression correlation coefficients for the various equations developed from API/GRI data ranged from 0.56 to 0.86; a single equation developed by combining all the data into one set had a correlation coefficient of 0.71. Thi
41、s compares; favorably with the four equations published by the EPA in “Protocols for Equipment Leak Emission Estimates (June 1993) that ranged from 0.45 to 0.87, and with the regression correlation coefficient published with the MMS Pacific OCS platform data which is 0.79. SDeciated Emissions and Ai
42、r Toxics Methane was the major fugitive hydrocarbon at all types of petroleum production sites. Hexane was found in levels of 2 percent by weight or less, while benzene and toluene were found at levels below 1 weight percent. Concentrations of xylenes and ethyl-benzene were usually near the laborato
43、ry method detection limits. Reaional Differences in Emissions No apparent regional differences have been found except for offshore platforms. InsDection and Maintenance More than 90 percent of the total emissions came from components with lSVs of 10,000 ppmv or more. Inspection and Maintenance (I to
44、 mass emission rates; 3. Develop profiles of speciated hydrocarbon emissions including air toxics; 4. Assess regional differences in fugitive emissions; 5. Assess control efficiency of Inspection and Maintenance programs. ScoDe This report presents data collected at four light crude production sites
45、, four heavy crude production sites, four gas production sites, four gas processing plants, and four Gulf of Mexico platforms. Correlation equations were developed from data collected at all five types of facilities. Fugitive hydrocarbon emission factors and air toxics weight fractions were develope
46、d from data at four types of 1-1 API PUBL*45B9 93 0732290 0537530 25b sites. A separate report on fugitive hydrocarbon emission factors and air toxics weight fractions for gas plants will be published after more field data are collected in a joint research effort with the EPA. The 1980 emission fact
47、ors for connections, valves, and open-ended lines are directly superseded by the new emission factors developed in this study. The limited number of uncontrolled pressure relief valves, pump :seals, compressor seals, and other components found during the study did not provide enough data to allow de
48、velopment of new factors for these components as separate types. Instead these and other miscellaneous components were grouped into one category called “Others“. The study produced two types of emission factors: 1) emission factors for use with component counts and, 2) emission factors for use with
49、Ws. Separate correlation equations were developed for connections, valves, open-ended lines, and other components. Emissions were speciated according to hydrocarbon length (number of carbon atoms) and type (aromatic and nonaromatic hydrocarbons). DESCRIPTION OF METHODOLOGY Sixteen onshore sites and four offshore sites were visited in the contiguous United States. A total of 184,035 components was screened according to US EPA Method 21 guidelines using portable monitoring insiruments. A total of 4,796 components gave lSVs of 1 O parts-per-
