Background:
Well testing provides a means of determining the production characteristics of a well. A well test can be conducted for a variety of reasons, including an evaluation of the productive potential of a well (incorporating wellbore flow capacity and reservoir limits), a measurement of the gas–oil ratio (GOR), a means to sample reservoir fluids, or some other specific item (refer to Annex A for a more detailed description of the various well tests for oil and gas wells).
For use in upstream measurement and allocation, a well test is referred to as a production well test and is defined as the fluid measurement of gas, oil, and water from a single well during a specified length of time under controlled operational conditions.
In this document, well testing is a well production testing job to find out production data from each well (oil, water and gas) per day. This data is important for Petroleum Engineers to analyze well and formation as a whole, whether the well is still producing good or requires a well service or workover job to maintain / increase the rate of production.
Scope:
This document is to provide an introduction on the documentation of production well testing management for well rate determination in production measurement and allocation.
Production well testing addressed in this document refers to measurement of gas, oil, and water quantities from a single well during a specified length of time under controlled operational conditions.
The intent of this document is to provide operators with a consistent and transparent approach for conducting, applying, and managing production well testing within an upstream measurement and allocation system.
It is not intended to prescribe a particular production well test method, or particular application of production well test data use in allocation.
Well Testing Methods
In this document, well testing is a well production testing job to find out production data from each well (oil, water and gas) per day. This data is important for Petroleum Engineers to analyze well and formation as a whole, whether the well is still producing good or requires a well service or workover job to maintain / increase the rate of production.
Well testing is carried out with 2 (two) methods, namely:
1) Manual Well Testing (MWT)
2) Automatic Well Testing (AWT)
Well Test – Requirements ?
Production well testing requirements are often cited in regulatory permits, commercial agreements, and operator’s policies. This can include test frequency and duration, and the use of the production well test measurement in well rate determination scenarios and/or allocations. The application of this document shall be in conformance with all applicable regulations, permits, and agreements.
All production well test requirements outlined in regulations, permits, or agreements shall be documented.
How? – Conducting a Production Well Test
Steps of Well Test :
- Preparation,
- Initiation and measurement,
- Validation, and
- Volume and rate calculations for separator, multiphase flow meter, and tank production well test systems.
Documentation and Record Retention
Documentation is a definite reference for the application of Well Test Management so that it can maintain the consistency of the quality of the results of well test data and / or maintenance (calibration / zero check) of measuring instruments.
The company should have a documentation system that can be used to track each well test data.
- Documentation includes:
- Guidelines (Guideline)
- Procedure (SOP / TKO)
- Work Instruction (WI / TKI)
- Forms / Records (Forms)
- Some forms needed (not limited to):
- Application for testing and / or calibration forms
- Sample acceptance and distribution forms (examples)
- Form analysis and / or measurement of examples
- Test report form and / or zero check / calibration
- Chemical inventory form
- Inventory form measuring instruments (meters, field instruments) & laboratory equipment
- Form PM measuring instruments
Documentation and record retention policies shall be instituted by the operator to provide an audit trail of the production well testing operation and results.
In addition to documented production well test requirements, recorded information and data should include:
- process flow diagram(s) denoting all equipment and flow paths in the production well test system;
- equipment list for the production well test system (e.g. meters, transmitters, samplers, analyzers, separators, etc.);
- performance specifications associated with the production well test equipment (e.g. meter uncertainty);
- established procedures associated with certification, calibration, verification, testing, and inspection of all production well test equipment;
- established procedures for conducting the production well testing operation;
- description of associated sampling methods, analysis, and frequency (all fluids);
- applicable well-specific fluid property information (e.g. oil and gas compositions);
- applicable well-specific equation of state (EOS) or fluid property correlations (PVT characterization);
- software versions for all associated computer calculations;
- historical accounting of previous production well tests;
- acceptance criteria used to evaluate the production well tests;
- contingency plans.
Develop the Well Test Operating Procedures
Procedures for conducting production well testing should be established and documented prior to production well testing operations. The procedures should include information relevant before and during the production well test, such as the sequence of events, equipment adjustments, data acquisition, and logging. In addition, pre-production well test activities such as fluids, production, and equipment verification steps should be included.
The well test operating procedure is made as a guide to the sequence of work that must be carried out before, during and after well testing takes place.
The production well test objectives should clearly define:
— production well test frequency, duration, and reporting;
— fluid sampling activities during production well testing;
— production well test use in well rate determination and production allocations;
— production well test use in well or reservoir evaluation.
This procedure is prepared based on the desired data type and type of equipment used.
- Adequate Work Guidelines:
- Operating procedures are made as instructions regarding the sequence of work that must be carried out before, during and after well testing takes place.
- (includes production well test preparation, initiation, measurement, validation, and volume and rate calculations for separators, and multiphase flow meters)
- Guidelines for a production well test,
- Guidelines for calculating production well test volumes and rates, and
- Guidelines for procedures for production well test data for use in measurement and allocation
According to the Company’s Operating Needs: This procedure is prepared based on the desired data type and type of equipment used
Develop the Procedure of Preventive Maintenance and Calibration – Well Test Tools
This procedure should includes (but not limited to):
- Frequency of zero check (calibration) of measuring instruments
- Implementation of Calibration (Zero Check)
- Acceptance criteria for measuring accuracy & precision
- Control the use of measuring instruments
- Control of calibration records & PM / routine check
- Indicators & Measures of Success:
- All measuring instruments are calibrated properly proven by a valid calibration certificate / zero check report.
- All measuring instruments function properly as evidenced by routine recording of PM / function checks.
References:
Standard Best Practise:
Applicable Standards/Code/Regulationa/Best Practices in upstream oil & gas industry should be referenced for and will be used as the main basis for developing and implementing the Well Test Management, as below:
American Petroleum Institute (API) – Manual of Petroleum Measurement Standards (MPMS):
- Chapter 20.1—Allocation Measurement;
- Chapter 20.2—Production Allocation Measurement Using Single-phase Devices;
- Chapter 20.3—Measurement of Multiphase Flow;
- Chapter 5—Recommended Practice for Application of Production Well Testing in Measurement and Allocation;
- Chapter 8.1, Standard Practice for Manual Sampling of Petroleum and Petroleum Products
- Chapter 11.1, Temperature and Pressure Volume Correction Factors
- API MPMS 5.3 : Metering Measurement of Liquid Hydrocarbon by Turbine Meters, Includes Addendum 1
- API MPMS 14.3.1 : Manual of Petroleum Measurement Standards Chapter 14 Concentric, Square-Edged Orifice Meters Parts 1 – General Equations and Uncertainty Guidelines
ISO/IEC:
- ISO/IEC 17025 —General requirements for the competence of testing and calibration laboratories;
- ISO/IEC GUIDE 98-3:2008 (EN) —Uncertainty of Measurement;
- ISO 5167-1 : Measurement of fluid flow
- ISO 9001:2015 Quality Management System – Requirements
- Clause 7.2 Competence
- Clause 7.5 Documented information
- Clause 8.1 Operational planning and control
- Clause 7.1.5 : Monitoring and measuring resources
- Directive 017 Measurement Requirement for OG, Release date: November 21, 2018 : Directive 017 consolidates, clarifies, and updates Alberta Energy Regulator (AER) requirements for measurement points used for AER accounting and reporting purposes, as well as those measurement points required for upstream petroleum facilities and some downstream pipeline operations under existing regulations.
- Measurement Guideline for Upstream Oil and Gas Operations, Version 2.0 : November 2018
Local Regulations:
- Keputusan Menteri Tenaga Kerja Dan Transmigrasi Nomor : KEP. 250/MEN/V/2007 Tentang penetapan standar kompetensi kerja nasional indonesia sektor industri minyak dan gas bumi serta panas bumi sub sektor industri minyak dan gas bumi hulu bidang produksi sub bidang operasi produksi
- PP no 2 th 1989 : standar nasional untuk satuan ukuran
- PTK-062 Manajemen Operasi Produksi Minyak Dan Gas Bumi;
- Pedoman Pelaksanaan Operasi Produksi dan Pelaporan Arus Minyak Dan Gas Bumi (PUPO-PPAM);
Additional Reading :
- Oil Well Testing Handbook
- Buku PK. TEKNIK PRODUKSI MIGAS Semester 3, terbitan Kementerian Pendidikan dan Kebudayaan Republik Indonesia, th 2013
- Buku PK. PROSES PRODUKSI MIGAS Semester 4, terbitan Kementerian Pendidikan dan Kebudayaan Republik Indonesia, th 2013
- Buku PK. TEKNIK RESERVOIR DAN CADANGAN Semester 3, terbitan Kementerian Pendidikan dan Kebudayaan Republik Indonesia, th 2013
Link/URL – Read More :
- Surface Well Testing: Guidelines for Data verification and Dealing with
Main Issues about Measurement Devices, https://www.linkedin.com/pulse/surface-well-testing-guidelines-data-verification-dealing-sabzi/ , read on 4 Dec 2018. - https://id.wikipedia.org/wiki/Akurasi_dan_presisi
- https://www.astm.org/Standards/D1250.htm
- https://upmforum.com/upm-forum-2018/presentation-lectures/Presentation%20Matt%20Zimmerman.pdf
- https://petrowiki.org/Well_test
- https://www.bcogc.ca/node/8283/download
- https://home.czu.cz/storage/52485_introductory-well-testing.pdf
- https://id.wikipedia.org/wiki/Pencatatan_Sumur
- https://www.coursehero.com/file/24971764/BAB-4-JENIS-JENIS-WELL-TEST-SUMUR-MINYAKdocx/
- https://id.scribd.com/doc/81961868/ANALISIS-UJI-SUMUR
- http://teknik-perminyakan-indonesia.blogspot.com/2015/03/pengujian-bs-w-penting-untuk-crude-oil.html