Research And Application Of CO₂ Pipeline Transportation And SC Injection Technology

CO₂ flooding is an important way to reduce CO₂ emissions and EOR as well as in Oilfield. Pilot test and expanding test are carried out in Daqingzijing Oilfield. With the development of Changling gas field which contains high content of CO₂, it is necessary to carry out research on key technologies such as CO₂ capture, pipeline transportion and injection of SC. After in-depth exploration of experimental, theoretical research and field trials, we made a breakthrough in CO₂ capture, pipelines and SC injection and other key areas of basic theory and technology.CO₂ and CO₂-containing gas physical parameters works illustrated were improve, CO₂ gas physical parameters and test phase were completed, recognizing the CO₂ density with phase change of the "mutation" and "gradual" laws; The formation of CO₂ capture technology, verification and improvement of amine France decarbonization process of natural gas containing CO₂, it is feasible to use Amine decarbonization technically when CO₂ content in natural gas less than 30%, membrane separation decarburization test is carried out; CO₂ pipeline optimization design and optimal operation model are established, the pipeline programs of CO₂ in gas, liquid and SC are studied for industrial test of CO₂ flooding in Daqingzijing Oilfield, as the basis of each recycle injection station, through technical and economic comparison argumentation, preferably a pipeline design; improved the liquid CO₂ injection technique, forming a SC CO₂ injection technique, a clear focus on SC CO₂ injection into consideration, phase behavior of CO₂ hydrate control methods, the design of SC CO₂ injection processes, SC built to run H59 CO₂ injection pilot plant, the maximum test pressure reaches 25 MPa, research and analysis in CCS projects abroad CO₂ gas reinjection system design features, a clear direction for optimizing CO₂ compressor; HSE risk control system of CO₂ flooding on ground engineering are improved, recognizing the production of CO₂ and CO₂ flooding diffusion of the outlet pipe leaks, analyzes of CO₂ purification, gathering, transportation, injection, separation, re-injection and other aspects of the risk measures proposed plans to improve the HSE system.The formation of "three kinds of application mode" : the station that skid-mounted injection to meet the pilot test: early transportation by tanker, injection by liquid, late by single well in H59, gas gathering and dehydration in single-well, short-distance gas pipeline, cold liquefied ammonia, liquid high-pressure injection, supercritical mixed gas injection, this model applies to smaller blocks scattered of CO₂ flooding pilot test. Concentrated injection modes to meet the expanded trial: it is feasible for the test area that more wells, larger scale and near the source of CO₂ gas block. For example, H79 pilot area adjacent CO₂ capture and storage systems in purification plant, using liquid CO₂ injection, CO₂ Flooding fluid produced gas-liquid separator and separated liquid recycle injection. SC injection modes to meet the industrial application: process simplification, economy, and adapt test area from a wide range of sizes and can be used for industrial promotion. For example, gas injection mode in H46 station of Daqingzijing oilfield: Changling gas field in the output of CO₂ as gas source, using gas pipelines, SC injection, all outputs of CO₂ flooding are reinjected by SC.The research program that 500,000 tons of CO₂ flooding to promote industrialization has been completed in Daqingzijing Oil field, it is predicted that the recovery of CO₂ flooding can increase by 10% or more comparaed to waterflood, CO₂ flooding by liquid injection and SC recycle injection are achieved, initially basic theory and methods of CO₂ flooding on ground engineering are established, CO₂ capture, pipeline transportion and SC injection technology series are formed, the first ground systems of CO₂ flooding that CO₂ trap- transportion- liquefaction – injection are built in China; the article describes the CO₂ flooding experimental studies, field tests and the results achieved, elaborated the theoretical understanding of CO₂ flooding, the key technology on ground works and made a clear understanding, and it is a guiding role for the domestic CO₂ storage, oil and gas field development and construction.