Material Selection Considerations for CO2 Sequestration Projects
a report by Paul Laws
President, OSG Materials Consultants Houston
Worldwide increases in energy demand coupled with a continued reliance on fossil fuel resources have contributed to a significant increase
in atmospheric levels of carbon dioxide (CO2). This increase shows no signs of slowing. According to the International Energy Agency’s World Energy Outlook 2007, the projected growth in energy demand will
translate into a 57 % rise in energy-related CO2 emissions by 2030. Scenarios for stabilising climate-forcing emissions suggest atmospheric
CO2 stabilisation can only be accomplished through the development and deployment of a robust portfolio of solutions, including: •
• •
• spent billions of dollars on research and development to address the
technical, engineering and safety issues related to CO2 production, transport, injection and containment in naturally occurring geological formations.
Today, the petroleum industry operates CO2 EOR projects in 74 fields and injects over 2.14 billion cubic feet (BCF) of CO2 per day.
significant increases in energy efficiency and conservation in the industrial, building and transport sectors;
increased reliance on renewable energy and, potentially, additional nuclear energy sources; and
deployment of carbon capture and storage (CCS).
CCS is the term that applies to an array of technologies through which CO2 is captured at industrial point sources, such as fossil-fuel combustion, natural gas refining, ethanol production and cement
manufacturing plants. Once captured, the CO2 gas is compressed into a supercritical phase and transported to a suitable location for injection
into very deep geological formations, such as saline reservoirs, mature oil or gas fields and potentially unminable coal seams, basalts or other
formations. Once injected, the CO2 is isolated from drinking water supplies and prevented from release into the atmosphere by a primary confining zone that includes a dense layer of rock that acts as a seal and through additional trapping mechanisms. In general, it is expected
that CO2 storage projects will become more secure over time as these additional trapping mechanisms take effect. This process is shown schematically in Figure 1.
It should also be recognised that the oil and gas industry has over 35
years of experience developing the transport and injection of CO2 for enhanced oil recovery (EOR). While constantly evolving, the technology, operating experience and regulatory requirements that have been developed for EOR are extensive. Since January 1972, when the world’s
first commercial CO2 EOR project commenced operation in the SACROC Unit, the American oil and gas industry has: •
• •
This report assesses the infrastructure required for CCS projects with a particular emphasis on the types of materials that are required for pipelines and wells, along with the issues and potential risks associated with these material options.
Components in a CO2 Sequestration System
Primary Types of CO2 Pipeline Existing CO2 pipelines operate at pressures ranging from 1,250 to 2,200 psi. Since most natural gas pipelines operate at pressures at or
below 1,200 psi, CO2 pipelines are constructed specifically for transporting CO2 and are normally listed as either type II or III pipelines. Acceptable CO2 and co-constituent concentrations for both pipeline types are shown in Table 1.
The majority of CO2 pipelines in North America can be listed as type II pipelines, which serve multiple sources and user lines and have a strictly
limited composition. Less common type III pipelines have relaxed composition standards compared with type II pipelines. The best example of a type III pipeline is the pipeline that connects the Dakota Gasification plant near Beulah, North Dakota with the Weyburn EOR
project in southern Saskatchewan. This pipeline carries a CO2 mix that has a relatively higher hydrogen sulphide (H2S) concentration. It should be noted that extra operational precautions are required at both the
drilled and completed 8,846 CO2 injection wells in Texas alone, in multiple lithologies;
drilled and completed 573 CO2 disposal wells in Texas alone, in multiple lithologies;
re-completed over 4,500 total wells for the Salt Creek, Wyoming
CO2 EOR flood, over half of which dated from the 1920s, of which 50 % were plugged and abandoned;
• cumulatively injected over 11 trillion standard cubic feet into oil and gas reservoirs;
• built almost 4,000 miles of high-pressure interstate CO2 pipelines; and © TOUCH BRIEFINGS 2011
source and the sinks when there are high H2S concentrations. As a result of the different composition standards, it will not be easy for
operators to connect type III pipelines to type II pipelines.
Type I pipelines do not exist in today’s CO2 EOR industry, but can be developed for a specific single use (i.e. a single CCS project). These pipelines can be applied to situations where case-by-case specifications
for CO2 composition are appropriate, based on the capture system. They cannot be connected to the existing CO2 EOR pipeline network of type II pipelines.
63
Transport of CO2 by pipeline will be necessary if large volumes of captured CO2 are to be stored in geological formations at short to medium distance from the capture location. For a number of countries,
including Norway and the UK, the preferred storage locations will be offshore, necessitating offshore pipelines between the capture and storage facilities.
Engineering & Construction
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124