Standards Resource & Research Request (SR 3 ) Form Committee on Petroleum Measurement

Transcription

1 Document Information Standard Designation: Title: Edition: Budget Year: 2019 Committee/Subcommittee: (check all that apply if a joint project) Priority Matrix Ranking: (to be completed by API) Proposed Action: API CPMA Wet Gas Sampling Study COPM CELE COLM COGFM X CPMA COMA COMQ COMET Priority 1 (Rank 10-15) New Standard Priority 2 (Rank 7-9) Priority 3 (Rank 6) Revise Current Standard Withdraw Current Standard X Research Only Proposed Funding Type: X Budget Request Special Solicitation Total Funding Request (Parts A & B): $ $80,000 Name of Submitter(s): Joe Landes Date: March 23, 2018 Part A Resource Plan I. Background and Information: 1. Explain the business need for the proposed action. Indicate potential cost savings to industry where possible. Current industry guidance documents for the collection of custody quality natural gas samples were written and evaluated for dry gas. However, many of the applications in the field require the extraction and collection of samples from gas streams which are at or below the hydrocarbon dew point and are therefore considered wet gas. An API workgroup should be established to evaluate if technologies or techniques are currently available which will allow for the extraction and collection of samples that are representative of the gas and liquid phases flowing through the wet gas product stream. Currently, samples are extracted and collected of only the gaseous phase product within both wet and dry sample streams. Downstream products, residue gas and NGL s are then allocated to each contributing source based on the heating value, relative density, and GPM calculated from each contributing gaseous phase sample. While this is a means of equivalently allocating sales products, the development of hydrocarbon wet gas sampling techniques could provide a more equitable process by improving the accuracy of fluid properties, and additionally by reducing uncertainties in flow measurements that rely on them. When applying the current dry gas sampling methodologies to hydrocarbon wet gas sampling, the uncertainty in the physical and analytical measurements becomes an unknown. The API workgroup will

2 1) investigate if the uncertainty in the collection of wet gas can be determined, and would 2) investigate techniques for the extraction and collection of a representative hydrocarbon wet gas sample which would reduce that uncertainty. The ability to extract and collect a representative hydrocarbon wet gas sample would provide a more accurate means of determining the heating value, density, and GPM, which would in turn provide a more equitable means of allocating sales products. The workgroup will establish data which will either: a) support techniques that provide samples which are representative, establish uncertainties of those techniques, and the limitations of those techniques where they fail to meet the established uncertainty expectations, or b) determine that no proven techniques exist for the collection of a representative hydrocarbon wet gas sample and that current techniques provide the best available analytical data. The data from the study could be collated into an API Technical Report with a view to subsequent development of an API Standard for this subject. 2. What is the scope of the standard? 3. Is this standard on the work program of another standards development organization (SDO)? Yes No X If yes, specify SDO and standard designation/project title/contact If yes, is the work being coordinated with the appropriate group? Are there special circumstances that would justify independent API initiation of the proposed action? 4. Are a volunteer chair and group of experts available to perform the proposed action? Please include names and company affiliation and indicate chair, if available. Joe Landes SPL Dave Curtis Anadarko Matt Zimmerman BP Robbie Lansangan Wood Darin George David Fish Welker Flavia Viana SWRI Eric Harman CEESI Dave Bell Bell Engineering Amin Amin Letton Hall Group 5. Is there a need to commit resources to supplement the development of the draft? Would a paid content specialist accelerate progress on the development/revision? Is there a readily available content specialist? No, No, Matt Zimmerman/Robbie Lansangan

3 6. Are there special format requirements for final document, i.e. knowledge of ISO template required), significant graphics, photos or equations) required that would need extraordinary resources? Yes No X If Yes, please provide details: 7. Please provide any other information that is pertinent to the proposed action. David Fish s paper from NGSTech, What are the implications of not initiating the proposed action? Include potential safety, reliability, environmental and financial impacts that may arise. Allocation depends on upstream measurement, which includes both wet gas metering and wet gas sampling. Gas transmission lines often have hydrocarbon liquids flowing alongside wet natural gas. While API 14.1 addresses dry gas sampling and liquid sampling, to date no baseline testing exists for wet gas and multiphase sampling. 9. Is there research proposed to accomplish the proposed action? Yes X No If yes, complete Part B of this form. II. Project Timing Proposed start date: January 2019 TG/WG: (estimated number of volunteers needed) 5-10 Proposed date draft will be ready for letter ballot: Content Management: ($ amount "if needed" or volunteer) PART B Research Plan I. Background and Information 1. Proposed Research Title: Testing of Basic Wet Gas Sampling Methods 2. Proposed Project Scope: The project will appraise the basic capabilities of methods intended to obtain representative samples of wet gas streams, i.e., natural gas streams carrying small amounts of hydrocarbon liquids. Such flows are common in production systems where sample analyses are used for production allocation. The phases proposed are as follows: Phase 1 decide on dedicated wet gas sampling methods to test; Phase 2 test dry gas methods on Type I flows and evaluate performance; Phase 3 test methods identified in Phase 1 on Type I flows and evaluate performance. Phases 2 and 3 of this project will focus on API Type I wet gas flows, which have Lockhart-Martinelli parameters of 0.02 or less, and will not include multiphase mixtures or wet gas mixtures in the ranges 0.02 < LM < 0.3.

4 An expanded scope for subsequent work would include mixtures in the API Type II range of 0.02 < LM < 0.3, and would possibly support the reinstatement and revision of API RP 44, Sampling Petroleum Reservoir Fluids (withdrawn in 2010). In Phase 1 of the project (non-funded, volunteer resources utilized), existing and prototype sampling methods and equipment will be nominated and chosen for testing by CPMA and other API committees with a stake in the project for Phase 3. API Type I conditions commonly found at field sites, including stream compositions and flow rates, will be considered in selecting flowing conditions of interest. Sampling equipment now in use will be considered in selecting sampling methods and other equipment for testing. If resources allow, multiphase flow modeling will also be used in selecting sampling methods for testing. In Phase 2 a baseline set of data will be collected in a test facility using API 14.1 compliant procedures across the flow regime ranges described in the table below. During previous API research for dry gas sampling at a similarly configured test facility, samples obtained near the hydrocarbon dew point (slightly below) yielded promising results. There was no further testing in that project since wet gas sampling was outside the scope of the work. For this project, a similar fluid (API Btu gas) will be used to determine additional uncertainties as the test conditions go below the hydrocarbon dew point. This will establish the baseline set of data for current practices and provide a target for future work. Wet Gas Section 1 Sim. 2 Seq. 3 LM = Sample Point 1 CV Sample Point 2 CP Sample Point 3 CV Sample Point 1 CP CV,CP Sample Point 2 CV CP,CV Sample Point 3 CP CV,CP Sample Point 1 CV CP,CV Sample Point 2 CP CV,CP Sample Point 3 CV CP,CV Sample Point 1 CP CV,CP Sample Point 2 CV CP,CV Sample Point 3 CP CV,CP Sample Point 1 CV CP,CV Sample Point 2 CP CV,CP Sample Point 3 CV CP,CV Sample Point 1 CP CV,CP Sample Point 2 CV CP,CV Sample Point 3 CP CV,CP Sample Point 1 CV CP,CV Sample Point 2 CP CV,CP Sample Point 3 CV CP,CV Control samples taken from dry gas section of flow loop Simultaneous collection Sequential collection

5 In Phase 2 of the project (for which this funding proposal is intended) data will be collected in a closed flow loop test facility with: closely controlled flow conditions, reference equipment to measure flow volumes and flowing conditions, reference equipment to sample and analyze single-phase gas through C9+, pipe diameters and separation equipment simulating common field production and gathering sites, and heaters and coolers to move the stream temperature between single-phase and two-phase conditions (dry gas and wet gas). The test fluid will have a high hydrocarbon dew point, so that it can transition between a single-phase gas and a wet gas stream as it warms and cools within the loop. Tests will be conducted at multiple (propose 7 points depending on budgetary constraints) Lockhart-Martinelli numbers ranging from 0 to 0.02, covering the range of API Type I flows. Test samples would be collected sequentially and simultaneously as shown in the table above using API MPMS Chapter 14.1 sampling methods that previously performed well near the hydrocarbon dewpoint. Simultaneously collected samples would be collected from sample points at different probe insertion depths. Sequential samples would be collected and analyzed to determine the precision. Dry gas samples collected simultaneously with the wet gas samples (along with online analyses) will be used to evaluate the uncertainty of the wet gas sampling. Collected samples will be analyzed through C9+ by the online GC at the test loop and retested at a laboratory with the capability of performing GPA 2286 extended analyses through C14+. Reference flow meters, single-phase sampling equipment, and a GC will measure and analyze the heated gas phase and the gas and liquid flows downstream of the separator. The wet gas sampling methods will be tested in the cooled wet gas stream, with wet gas meters used to measure the local flow rates. Finally, a mass balance and composition balance on the entire loop will be used with an uncertainty analysis to evaluate the performance of the wet gas sampling methods. In the potential Phase 3, the prototype methods chosen from Phase 1 will be tested in this closed flow loop test facility to determine if they offer a reduction in uncertainty. The same series of tests would be performed as in Phase 2. In potential future phases (assuming that Phase 2 does not identify the limit of LM parameter within uncertainty expectations), the best performing methods from Phase 2 and 3 would be tested to determine the limitations of wet gas sampling. Depending on CPMA recommendations, future phase tests may involve: a field site with realistic or variable wet gas flowing conditions of interest to CPMA and other stakeholders, or evaluation of the sampling methods with multiple fluids (propose 2 more if within budgetary constraints) in a test facility with API Type II flows (Lockhart-Martinelli numbers up to 0.3). 3. Research Amount: $ For Phase 2: $80, What is the business need for the proposed research? Understanding the effectiveness and uncertainty of hydrocarbon wet gas sampling can have a large impact on the allocation of oil and gas assets. The true composition and properties of wet gas can only be determined through a valid protocol for wet gas sample collection and analysis, which this work

6 proposes to address. Knowing the effectiveness and uncertainty of hydrocarbon wet gas sampling will allow users and operators to better control operations and reduce costs. The need for additional gasliquid separation, the assessment of separator efficiency, and operations such as stream commingling can also be influenced and optimized by accurate wet gas sampling. 5. Is the proposed research edition-specific for a single standard or will it result in technology enhancement for multiple standards? Yes X No If multiple standards, please cite the standards effected: MPMS Chapter Research Timing: X Research is necessary for development of a standard Research can be done concurrent with revision. 7. How does the research support the proposed action identified in Part A? Typical well site equipment includes flow meters, separators, and other equipment that produce singlephase measurement data for allocation purposes. Significant progress has been made in the field of wet gas flow measurement since the introduction of multiphase metering technology in the 1990s. If applied to allocation, these advances represent an opportunity to reduce Capex, Opex, and reduced measurement uncertainty. Proven methods of wet gas sampling could provide additional sources of accurate measurement and reduced expenses. If combined with multiphase meters, using the same approach as combining volume and composition measurements in pipelines, the improvements in allocation accuracy and reduced expenses could be greater than the individual contributions from either technology alone. 8. Is a joint industry project (JIP) a possibility? Yes X No If Yes, with whom? GPA Midstream and/or PRCI 9. Are there opportunities for leveraged research with other organizations? Yes No What organizations? see above 10. What are the implications of not performing the proposed research? Not having a procedure or equipment designed for sampling wet gas in support of wet gas flowmeter fluid configuration. II. Dates and Funding: Estimated Completion Date Phase 2 - October 2020 Prior Research Funding Requested Anticipated Future Research Funding Needs $ Year 2: $ 80,000 Year 3: $ Year 4: $

7 PART C Proposal Feedback/Approval Information For API Use ONLY SC comments to Proposer/WG: Date approved by subcommittee: COPM comments: Date approved by COPM: Date entered into API Publications DB: