#1General EGU by 2020 Methane emissions from shale gas production sites in Sichuan, China (EGU2020-20729) Ming Xue¹,2, Yiwei Zhao1,2,3, Jun-xin Fan1,2, Dongdong Cao1,2 1. State Key Laboratory of Petroleum Pollution Control 2. CNPC Research Institute of Safety and Environmental Technology 中国石油 Mich 3. China University of Petroleum 中国石酒 May 2020#2120 Background Shale Gas Production Boosting in China in Recent Years Climate Challenge caused by Oil and Gas Production are Raising Attention Nine major emission source including Pneumatic Controllers, etc. were identified Gas is treated and stored prior to entering distribution system Shale Gas Production (X 108 m³) 100 80 ཕྱྀ ཎྱཾ ཏྲྱ ལྔ རྔུ རྫུ 60 45 >100 91 79 12 0.1 2 0 2012 2013 2014 2015 2016 Year 2017 2018 Shale Gas Production in China (Modified from Zheng et al., 2018) Flowback water returns to the surface and is impounded prior to treatment or reuse SHALE GAS DEVELOPMENT A vertical well more than a km deep is 300m gradually turned through 90° angle and continued up to 3km horizontally. Hydraulic fracture occurs with 7-18 million liters of water which has been mixed with sand and chemical amendments to protect down-well equipment and optimize flow conditions. 700m Fracture water is pumped at high pressure to fracture the formation 1100m solids and increase permeability. Sand or other "proppant" flows into the new fissures to retain the newly introduced permeability as down-hole pressure decreases with the flow of the fracture 1500m water and gas to the surface. Gas-bearing Shale Formation Sand "proppant" holds open new permeability as pressure is released at the well head High-pressure water fractures formation and increases permeability of the formation Formation Gas and fracture water return to surface 0 D Newly introduced fracture in shale Well Casing Perforation and Overview of Shale Gas Production Process (Dzombak et al., 2011) 2#3Background GHG Inventory of O&G Industry in China Methane emission factors are from the Guidebook of 2005 Instead of component-level, most emission factors are based on facility-level, especially for natural gas production Natural Gas Exploration Wellhead Gas Gathering Station L-Metering/Distrubuting Station Gas Storage Station Natural Gas Processing Natural Gas Transmission Compressor Station Metering Station Pipelines Pigging Station . - Venting -27.9 ton/Tyr each) 23.6 ton/(yr each) 1 Fugitive 2.50 ton/(yr each) • -8.5 ton/(yr each) 58.4 ton/(yr each) 403.4 ton/1 bcm 85.05 ton/(yr • each) 31.50 ton/(yr • each) 0.85 ton/(yr each) 10.0 ton/(yr⚫ each) 138.3 ton/1 bcm • 10.05 ton/(yr • each) 13.52 ton/(yr each) 5.49 ton/(yr • each) 0.001 ton/(yr • each) (NDRC, 2014)#4Background Study Area 塔 簽 யம் Shale Gas Region 2019.12 39.羌塘南40.昂拉41.伦波拉42.比如43.象泉河44勤45.定日岗巴 46宜夜47,日都48.苏北49.江仅50.開庭51.52.楚雄53兰坪思孝 4百色 55.十万大山 56 三水57.雷琼58.察新59.北黄海 60、台西 列,台西南62北部湾63.双峰南64.笔架南5.中國6.郑和67.礼乐灌 68.西巴拉草69万安西 70.安渡滩 北 D 面积为210万Km²面积为1~0.5万 油气田 油气显示 沉积盆地(注名) Km²沉积盆地 CHILD 面积为10-1万m² 未变质古 油气井 【及已见工业油气井生界区 南海诸岛 (Modified from Zou et 3 al., 2018) Annual Production of the sub-basin: 0.5 billion m³ dry gas Investigation Period: Dec. 25, 2019 to Jan. 5, 2020 Type: Well sites (18 sites with 79 wells)#5Background □ Basic Setting for Downwind Measurements and Methane Mapping Downwind Measurements (OTM33A): Picarro® G2301, McGill® 3D wind anemometer Site Patrolling: Picarro® G4302, GPS PICARRO Picarro G2301 CO₂/CH4/H₂O 5#6Our Investigation tried to answer the following questions: 1. What's the major methane emission source for the shale gas sites? 2. What's the methane emission rate for the shale gas well sites? 6#7Methane Emission Source □ Emission Source Flowback water tank was the major source ➤ Chemical injection pumps were from 2 sites ➤ Leakage from valves were fixed after inspection Valves, 14.0% Separator, Pneumatic 7.0% Controllers, 4.7% Flowback Water Tanks, 41.9% Chemical Injection Pumps, 32.6% 7#8Methane Emission Source ☐ Pneumatic Controller Pneumatic controllers from separators were mostly no-bleed or low-bleed Well sites constructed after 2018 used electric controllers All the controllers for chemical injection pumps were natural-gas driven Pneumatic Controllers for chemical injection, 24% Electrical Controllers, Pneumatic Controllers for separators, 24% 52% 8#9Methane Emission Source Methane Mapping ➤ Highest methane concentration inside the sites from 2.54 to 459 ppm Over 55% of the sites has the highest methane concentration <50 ppm No. of Well Sites 12 10 00 2 0 0-50 50-100 100-350 >350 Highest Methane Concentration (ppm) 9#10Methane Emission Rate □ Application of vehicle-based measurements Site No. Average wind speed (m/s) Methane Release Rate (kg/hr) Stability Class (PGI) 13 11 0.3-0.8 3 2. Station 11 20 15 0.02-0.2 1.5 3 3 2.56 10 2.54 2.5 5 2.48 2.44 4 2.4 2.38 3 2.34 2.2 2.3 2.28 2 2.24 2.2 1 2.18 2.14 2.1 Station 3 10#11Take home Message Application of electric controllers could reduce methane emission from shale gas development in China ➤ Flowback water tank is the major source of shale gas production sites, and mitigation options need to be considered. In mountainous areas such as Sichuan Basin, China, methane quantification methods other than OTM-33A may be applied. 11#12Contact: Ming Xue Ph.D/Senior Engineer Rm 615, No.1 Huanghe North Street, Changping District, Beijing 102206, China Tel: +86 10 8016 9570 Email: [email protected] Funding Info: National Key Science and Technology Projects of China (Grant No. 2016ZX05040-004) and CNPC Science and Technology Development Projects (Grant No. 2016E-1208). References: Zheng, M., J. Li, X. Wu, S. et al. 2018. Natural Gas Geoscience 29 (10):1382-1797. Dzombak, D. A., K. B. Gregory, and R. D. Vidic 2011.Elements 7 (3):181-186. Zou, C., Z. Yang, D. He et al. 2018. Petroleum exploration and development 45 (4):575-587. National Development And Reform Commission NDRC, 2014.