We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
济阳坳陷陆相页岩油气藏组合缝网高导流压裂关键技术.
- Authors
朱海燕; 焦子曦; 刘惠民; 周广清; 王建东; 张潦源
- Abstract
Shale oil and gas reservoirs in the Jiyang Depression have complex characteristics, such as great burial depth, complex structure, rapid sedimentary facies change, developed lamina and high oil viscosity, which make it difficult to implement sufficient stimulation by using the conventional network fracturing technology. As a result, the production rate after fracturing is low and declines fast. Therefore, it is urgent to research and develop a suitable new fracturing technology for the formation of complex fracture networks with long-term high conductivity. Based on the idea of geology-engineering integration, this paper researches geological-engineering double sweet spots evaluation, four-order fracture network construction, and main fracture pulse sanding theories and technologies, and develops and applies the key technologies of high-conductivity combined network fracturing. In addition, a "geological-engineering" double sweet spots evaluation model considering "cutting-core-borehole-reservoir" is established. A new fracturing fluid combination mode is constructed, in which, CO2 and acid are combined to reduce fracturing pressure, low-viscosity fracturing fluid is used to create complex fracture networks and high-viscosity fracturing fluid is used to promote fracture height growth. A four-order fracture network system of "wide main fracture + branched fracture + self supporting fracture + acidizing wormhole fracture" is formed for multiple-layer superposed reservoirs after fracturing. A new sand high-conductivity network fracturing method is proposed, which conducts pulse sanding in main fractures and continuous sanding in branched fractures. Eventually, a new high-conductivity combined network fracturing technology for shale oil reservoirs is formed, i.e., "arranging fractures through geological-engineering double sweet spots + combining CO2 and acid to reduce fracturing pressure and promote fracture development + increasing fracturing fluid viscosity + performing pulse sanding in main fracture". And the following research results are obtained. First, the 3D "geological-engineering" double sweet spots evaluation model, which fully considers the characteristics of shale oil and shale enrichment, movability and shale lamina, is helpful in the optimization of well location layout, fracturing zone and perforation location. Second, the new fracturing fluid combination mode with combined CO2 and acid to reduce the fracturing pressure, low-viscosity fracturing fluid to create complex fractures and high-viscosity fracturing fluid to promote fracture height growth is helpful in increasing the complexity of fracture networks after fracturing. Third, the four-order fracture network system of "wide main fracture + branched fracture + self supporting fracture + acidizing wormhole fracture" is formed in multiple-layer superposed reservoirs after fracturing, and a new sand high-conductivity network fracturing method of pulse sanding in main fractures and continuous sanding in branched fractures is proposed, which is conducive to improving the long-term conductivity of fracture networks. In conclusion, this new technology solves the problem in the economic and efficient development of high-viscosity shale oil in the continental shale oil and gas reservoirs of the Jiyang Depression, and provides theoretical and technical support for the stimulation of similar shale oil and gas reservoirs in the same block.
- Publication
Natural Gas Industry, 2023, Vol 43, Issue 11, p120
- ISSN
1000-0976
- Publication type
Article
- DOI
10.3787/j.issn.1000-0976.2023.11.011