CO₂ storage safety and leakage monitoring in the CCS demonstration project of Jilin oilfield, China

Abstract

Jilin oilfi eld is conducting the fi rst large-scale demonstration project on CO 2 storage and enhanced oil recovery (EOR) in the northeast of China. A comprehensive monitoring program has been designed and deployed in the target reservoir of block H-59 using a wide range of techniques to monitor the injection and production systems, the CO 2 migration fronts, and potential CO 2 leakage pathways. Tube fault detection, corrosion inhibitors, anti-CO 2 corrosion cement, and production dynamic analysis have been adopted to guarantee the safety at the well site. CO 2 movement in the reservoir is detected mainly by gas tracer, electric spontaneous potential measurement, and fl uid sampling. Nearsurface environmental monitoring is also conducted around the injection site. Field experience has shown that the monitoring targets should be focused on the reservoir, near-surface, and injection and production systems. Applying monitoring techniques to ensure the integrity of wellbores can not only prevent the leakage of CO 2 , but also avoid the blind expansion of monitoring program scopes. It is reliable and economical to take full advantage of techniques based on wellbores to monitor CO 2 movement in oil reservoirs with dense well patterns. Up to April 2013, nearly 21.7 × 10 4 tons of CO 2 has been injected without obvious leakage caused by integrity failure of wells or the geological structure of reservoir. More than 96% of injected CO 2 has been safely stored with the rest of injected CO 2 normally breakthrough in the production wells. The preliminary monitoring experience obtained can provide valuable guidance for the future enlarged Jilin project and other CO 2 EOR and storage operations.

Preliminary Assessment of CO2 Storage Potential in the H-59 Block in Jilin Oilfield CCS Project

“…The original gas-oil ratio is 35 m 3 /ton corresponding to a bubble point of 7.31 MPa. The salinity of the formation water is between 10229-19320 mg/L (Zhang et al, 2014). In addition, the core analysis shows that the reservoir lithology of the H-59 block is mainly siltstone associated with a small amount of fine sandstone and muddy siltstone.…”

“…18 injectors and 60 producers will be involved. Then CO 2 injection will be extended to other blocks of Daqingzijing region with more than 200 well groups covered [9] . The captured CO 2 from Changling gas field close to the H-79 block which has a CO 2 concentration of 21-23 mol% will be used for the second and full-scale phases of CO 2 EOR and storage in the Jilin oilfield.…”

Identification of potential CO2 leakage pathways and mechanisms in oil reservoirs using fault tree analysis

“…As a result, it is not seriously considered. Geological storage, which is different from surface mineralization and ocean storage, is widely accepted as the best short‐to‐medium term option to significantly reduce anthropogenic CO 2 from the atmosphere 8,11–15 . Geological storage refers to injecting CO 2 into geological structures and storing it permanently or for long periods of time, in the order up to millions of years 8 .…”

“…The CO 2 monitoring and control technologies have been paid increasing attentions during the CO 2 storage demonstration projects in order to accurately and timely master the condition of CO 2 stored in geological structures 14,31 . Different monitoring technologies are used, 32,33 such as 4D seismic, microseismic, cross‐well, electrical resistivity tomography, electric spontaneous potential, well fluid sampling, gas tracers, carbon isotope, ground water sampling, soil gas sampling, and air sampling, which can be classified into two different methods according to their monitoring subjects: reservoir monitoring methods and near‐surface monitoring methods.…”

Evaluating the Sealing Effectiveness of a Caprock-Fault System for CO2-EOR Storage: A Case Study of the Shengli Oilfield

“…In China, several CO 2 -EOR projects have been conducted by PetroChina, Yanchang Petroleum, and Sinopec in the Jilin Oilfield, Jingbian Oilfield, and Shengli Oilfield, respectively [8,[12][13][14]. The Shengli Oilfield (Figure 1) is the target site in this paper.…”