US 11,719,658 B2
Method of cement for well cementing in penetrated hydrate layer
Yuhuan Bu, Qingdao (CN); Shengda Shen, Qingdao (CN); Chang Lu, Qingdao (CN); Huajie Liu, Qingdao (CN); Shenglai Guo, Qingdao (CN); Xun Shan, Qingdao (CN); and Rui Ma, Qingdao (CN)
Assigned to CHINA UNIVERSITY OF PETROLEUM (EAST CHINA), Qingdao (CN)
Filed by CHINA UNIVERSITY OF PETROLEUM (EAST CHINA), Qingdao (CN)
Filed on Nov. 28, 2022, as Appl. No. 17/994,420.
Application 17/994,420 is a division of application No. 17/580,687, filed on Jan. 21, 2022, granted, now 11,567,018.
Claims priority of application No. 202110082094.1 (CN), filed on Jan. 21, 2021; and application No. 202110746567.3 (CN), filed on Jul. 1, 2021.
Prior Publication US 2023/0091934 A1, Mar. 23, 2023
Int. Cl. E21B 33/14 (2006.01); G01N 25/18 (2006.01); E21B 49/02 (2006.01); G01N 33/38 (2006.01)
CPC G01N 25/18 (2013.01) [E21B 33/14 (2013.01); E21B 49/02 (2013.01); G01N 33/383 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A design method of a cement for well cementing in a penetrated hydrate layer, wherein a low-hydration, early-strength, and heat-insulating cement slurry system is used during the well cementing in the penetrated hydrate later, and the penetrated hydrate layer is a hydrate layer penetrated by a casing pipe, comprising the following steps:
(1) collecting a formation sample of a cementing-target penetrated hydrate layer, testing physical parameters of the formation sample, and acquiring environmental parameters of the cementing-target penetrated hydrate layer;
(2) analyzing the physical parameters of the formation sample, and determining early strength performance requirements, hydration heat performance requirements, and heat insulation performance requirements of a cement slurry meeting cementing conditions based on field operation requirements;
(3) according to the early strength performance requirements of the cement slurry, testing effects of various early-strength agents, and selecting an early-strength agent with optimal performance from the various early-strength agents;
(4) according to the hydration heat performance requirements of the cement slurry, testing effects of various low-hydration-heat materials, and selecting a low-hydration-heat material with optimal performance from the various low-hydration-heat materials;
(5) according to the heat insulation performance requirements of the cement slurry, testing effects of various heat-insulating materials, and selecting a heat-insulating material with optimal performance from the various heat-insulating materials;
(6) preparing the early-strength agent with the optimal performance, the low-hydration-heat material with the optimal performance, the heat-insulating material with the optimal performance and the cement slurry into the low-hydration, early-strength, and heat-insulating cement slurry system to adjust performance of the cement slurry, such that the cement slurry has low hydration, early strength, and heat insulation performance and meets requirements of a cementing construction;
(7) using a performance evaluation device of a cement for well cementing in a penetrated hydrate layer to simulate a cementing process of the penetrated hydrate layer, and determining whether performance of the low-hydration, early-strength, and heat-insulating cement slurry system meets the requirements of the cementing construction; and if the requirements of the cementing construction are met, proceeding to step (8), and if the requirements of the cementing construction are not met, repeating steps (3) to (6); and
(8) estimating a cement slurry injection volume required by the cementing-target penetrated hydrate layer, and injecting the low-hydration, early-strength, and heat-insulating cement slurry system meeting the requirements of the cementing construction into the formation sample in a form of a displacement liquid according to field operation conditions and corresponding construction parameters until the cement slurry reaches a predetermined solidification range.