Selective cluster-by-cluster fracturing technology for horizontal wells in shale gas reservoirs

Abstract

The invention discloses a shale gas reservoir horizontal well selective cluster-by-cluster fracturing technology. The technology comprises the steps that a horizontal well section is divided into a plurality of clusters, and 1-4 clusters of jet perforation primary fracturing and multiple times of cluster-by-cluster fracturing are conducted through a continuous oil pipe each time to complete fracturing transformation of the horizontal well; in the later stage of primary fracturing, a sand plug is used for blocking a seam to carry out cluster switching, the first construction cluster uses the continuous oil pipe and a casing annulus to conduct primary fracturing or light bushing fracturing, the second to fourth construction clusters lift the continuous oil pipe out of a pithead for light bushing primary fracturing, and full bore of a whole shaft is kept in the fracturing process. Clustering and cluster switching are achieved through oil pipe multi-cluster jet perforation and seam manualplugging in the later stage of primary fracturing, mechanical packers are not needed, and selective cluster-by-cluster fracturing can be implemented in the horizontal well in any sequence at any position; the full bore of the shaft is kept all the time in the whole construction process and after construction, so that transformation size optimizing control over the shale gas horizontal well is achieved.

Description

technical field [0001] The invention relates to a method for fracturing horizontal wells in shale gas reservoirs, in particular to a selective cluster-by-cluster fracturing process for horizontal wells in shale gas reservoirs. Background technique [0002] At present, composite bridge plug staged volume fracturing technology is commonly used in the fracturing stimulation of shale gas horizontal well reservoirs in the Sichuan Basin. Complexity, overall achieved a good transformation effect. However, for shale gas reservoirs with strong inter-stage heterogeneity, it is difficult to achieve targeted stimulation; at the same time, because the current staged technology is to perform staged fracturing in the order from point B to point A in the horizontal well section, In the case of casing deformation, we can only abandon some intervals or it is difficult to achieve the purpose of staged stimulation. As of the end of 2016, the statistical results of Weiyuan Changning shale gas h...

AI Technical Summary

Problems solved by technology

However, for shale gas reservoirs with strong inter-stage heterogeneity, it is difficult to achieve targeted stimulation; at the same time, because the current staged technology is to perform staged fracturing in the order from point B to point A in the horizontal well section, In the case of casing deformation, we can only abandon some intervals or it is difficult to achieve the purpose of staged stimulation. As of the end of 2016, the statistical results of Weiyuan Changning shale gas horizontal wells show that the cumulative length of casing deformation is about 13700m, which affects the number of fracturing stages. reach 176 segments

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