28th February 2017 Version 1 University of Western Australia 1 CHPR5521 Term Project Brief The term project is designed to provide students with a summative flow assurance and gathering engineering experience, by applying heuristics, models and computer simulations from the classroom toward a practical oil and gas field. In this project, students will work individually to propose a subsea field development concept based on an assessment of flow assurance risk. The location and layout of the potential asset are shown in Figure 1, showing three separate reservoirs: Field A, a 200 MMstb shallow light oil reservoir at 300 m; Field B, a 116 MMstb black oil reservoir at 1300 m; and Field C, a 2.6 Tcf gas reservoir at 600 m. There is an existing shore facility with a facility-trunkline connection (shown as the black circle on the corner of the grey rectangle in the top left corner) to which the production fluids must be transported. Field A began production in 2012 and has a 12 inch trunkline from the manifold to shore which the reservoir fluids are produced from, the trunkline contains a choke at the manifold. The receiving facility may operate between 1 and 40 bar. We are now designing Fields B and C, the earliest possible first gas/oil would be 2022 with planning and construction. Example phase envelopes are shown in Figure 2 and reservoir pressure and water as a function of production are present in Tables 1 and 2. You may assume that the manifold temperature for reservoirs A, B and C is 95 °C throughout their production lifetime. Figure 1: Seafloor bathymetry and location of potential assets relative to shore facility This project will present you with a key overarching design challenges to consider: Will Fields B and C deploy a tieback into the subsea infrastructure of Field A or have independent infrastructure? Shore Facility 1400 m 1400 m Facility-Trunkline Connection 1320 m Field B Field A Field C 100 km Field A-Facility Trunkline 28th February 2017 Version 1 University of Western Australia 2 Additional Project Information Figure 2: Example phase envelopes for light oil, black oil and gas condensate Table 1: Water cut and reservoir pressure as a function of cumulative production for Fields A and B Field A Field B Cumulative Oil Production Water Cut Pressure Cumulative Oil Production Water Cut Pressure MMstb % bar MMstb % bar 0 0 93 0 0 234 44.4 5 87 25.8 6 227 85.5 16 80 49.6 16 221 128.2 36 74 74.4 36 214 157.3 59 66 91.2 60 207 172.6 74 63 100.1 75 203 184.6 84 60 107.1 84 199 193.2 89 57 112.1 90 196 200 95 54 116.0 94 193 204 96 52 118.3 96 191 C C 0. 25. 50. 75. 100. 125. 150. 175. 200. 225. 250. 275. 300. 325. 350. 375. 400. -50. 0. 50. 100. 150. 200. Pressure / bar Temperature / degC Light Oil Light Oil Wax Curve Black Oil Black Oil Wax Curve Gas Condensate 28th February 2017 Version 1 University of Western Australia 3 Table 2: Water saturation of gas and reservoir pressure as a function of cumulative production for Field C Field C Cumulative Gas Production Water Saturation of Gas Pressure Tcf % bar 0 100 113 0.57 100 107 1.09 100 101 1.63 100 94 2.00 100 86 2.20 100 82 2.35 100 79 2.46 100 76 2.55 100 74 2.60 100 73 28th February 2017 Version 1 University of Western Australia 4 Draft Project Report The draft project report submission is an optional activity. If you choose to submit an interim report, it is due by 11:59 PM on the 14th May 2017 and must be uploaded via LMS (a submission link will be provided). The draft report is meant to be as complete as possible, with the understanding that minor portions of the lecture content (Class 6) will not be included yet. The draft report is not intended to be a “short-form” of the final report, but rather a draft that adheres to the same guidelines and objectives as listed below for the final report. The purpose of this draft report submission is to receive an in-depth critique of your work, without being marked. This will allow you to polish the final report prior to submission, and consider any missing components in the project. Final Project Report The final project report is due by 11:59 PM on the 28th May 2017and must be uploaded via LMS (a submission link will be provided). There is a 20-page limit on the report, which does not include appendices. The deliverables within this project will be divided into four technical sections (A-D, described below). Answers to contextual questions must be fully supported by heuristics, hand calculations, and OLGA computational results; unsupported answers are irrelevant in technical sections. Description of results must explicitly describe any assumptions employed. These design questions must be addressed and supported to receive a satisfactory mark on the project, but are not all-inclusive; submissions may incorporate additional content deemed necessary, provided the content (i) is relevant to the project’s scope and (ii) does not duplicate discussion from elsewhere in the final report. 28th February 2017 Version 1 University of Western Australia 5 Report Breakdown Executive Summary This technical report should be accompanied by a one-page (strict limit) executive summary, which conveys the most important design recommendations. The summary should not contain excessive technical jargon or complex analyses; it should concisely explain the primary design choices that would be appropriate for a non-technical audience. Section A: Production Network This content must address the following five design questions: 1. What is the proposed production strategy for the oil and gas, including any topsides facilities and pipeline network? 2. Provide details on the expected flow regime in each tie-back. Are any pipe sections operating in or near a slugging regime (either terrain-induced or hydrodynamic)? 3. What are the steady-state fluid (gas, oil, water) flow rates of the tie-back(s)? 4. What are the steady-state pressure drop profiles in the tie-back(s)? 5. What are the expected temperature profiles for the tieback(s)? Section B: Gas Hydrate Thermodynamics This content must address the following three design questions: 1. Where in the system are hydrates stable during steady-state flow? 2. What is the expected steady-state hydrate growth rate for each pipeline? Describe the inherent risk in operating the pipeline(s) without any hydrate solution. 3. What is the severity of formation if the pipeline is shut-in to the point of thermal equilibrium with the ocean, and then rapidly restarted? Section C: Hydrate Risk Management This content must address the following five design questions: 1. Describe the expected plugging mechanism for all pipelines. 2. Is pipeline insulation viable to prevent hydrate formation during cold restart in any line? 3. How much MEG must be injected to prevent hydrate formation during cold restart? 4. Can KHIs or AAs be used as a management strategy in during cold restart in any line? 5. What is your recommended operational method for hydrate management during (i) steady-state, (ii) cold restart operations, and (iii) toward the end of field life? Section D: Wax, Asphaltene, and Corrosion Management This content must address the following four design questions: 1. Do you expect wax dropout during steady-state and/or shut-in operations? 2. Assess the severity of wax formation (if applicable) and prescribe a pigging frequency. 3. Do the oil-phase compositions indicate asphaltenes may precipitate in any line? What is the expected deposition rate of asphaltenes, if applicable? 4. Assess whether internal corrosion may be a risk for any pipeline, and proscribe a corrosion management strategy. Section E: Way Forward This content must address the following two design questions: 1. What are the weakest assumptions you have made throughout this design analysis? 2. In your opinion, what are the five key technical questions that must be addressed through simulation and/or experimental validation in the next development stage of this project? 28th February 2017 Version 1 University of Western Australia 6 Project Assessment Table 3: Distribution of marks for each section of the Term Project. Report Section Maximum Points Executive Summary 10 Section A: Production Network 20 Section B: Gas Hydrate Thermodynamics 15 Section C: Hydrate Risk Management 15 Section D: Wax, Asphaltene, and Corrosion 10 Section E: Way Forward 10 Presentation of Results 20 Table 4: Marking criteria for Executive Summary. Criterion % of total mark No significant contribution or totally ignored 0 Summary fails to capture or describe major design decisions. 30 Adequate description of major design decisions with lack of clarity or inappropriate level of technical detail. 60 Complete description of major design decisions, with appropriate supporting evidence and clear description. 80+ Table 5: Marking criteria for Section A-E. Criterion % of total mark No significant contribution or design questions totally ignored. 0 Student conveys limited understanding of design questions, with partial use of heuristics or hand calculations to provide an engineering estimate 30 Design questions are addressed with both hand calculations and OLGA simulations (when applicable), and the results are interpreted to support a design decision. 60 Using both hand calculations and OLGA (where applicable), students can elucidate the advantages and disadvantages ; the design recommendation is 80 accompanied by well-informed discussion of operational strategy. 80 Students demonstrate a superior ability to comprehensively describe steady- state and transient flow (with hand calculations and OLGA, where applicable), to recommend design decisions and operational strategies. Students can identify the assumptions behind critical model and simulation results, to identify which fundamental experiments/analyses could improve their recommendation. 90+ 28th February 2017 Version 1 University of Western Australia 7 Table 6: Marking criteria for Presentation of Results. Text Criterion Graphic/Figure Criterion % of total mark Unreadable Illegible 0 Many spelling and sentence structure Low information density, missing errors labels, incorrect significant figures Many spelling and sentence structure Low information density, missing errors labels, incorrect significant figures 20 Moderate (5+) spelling and sentence structure errors Low information density, poorly labelled graphs/charts 50 Minor (< 5) spelling errors Moderate information density 60 Flawless High information density 85+