Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. O...Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.展开更多
Neomysis awatschensis was collected on the west coast of Jiaozhou Bay, Qingdao in 1992 and acclimated in the laboratory conditions. The acute toxicity method using 4~ 6 day juvenile mysid of this species is studied. T...Neomysis awatschensis was collected on the west coast of Jiaozhou Bay, Qingdao in 1992 and acclimated in the laboratory conditions. The acute toxicity method using 4~ 6 day juvenile mysid of this species is studied. The species is compared with M. bahia in taxonomy, geographic distribution, morphology, as well as the sensitivity to reference toxins. Based on the results, we recommend N. awatschensis to be a standard marine organism for toxicity test in China and the method to be applied in toxicity evaluation of drilling fluids. In this paper, we report the results of the above studies and the application of the method in the evaluation of several drilling fluid products.展开更多
The finite element method was used to simulate the currents of Jiaozhou Bay and the nearcoast areas, and then established the model of the transport and diffusion of suspended particulate matter there. The transport a...The finite element method was used to simulate the currents of Jiaozhou Bay and the nearcoast areas, and then established the model of the transport and diffusion of suspended particulate matter there. The transport and diffusion of dredged matter near the discharging field were estimated; and the results were used to analyze the effects of the suspended particulate matter on the marine environment.展开更多
Crossed-dipole acoustic logging technology is mainly used to measure shear wave and determine the anisotropy or fractures of formation in the fi eld of acoustic logging.Based on the propagation characteristics of dipo...Crossed-dipole acoustic logging technology is mainly used to measure shear wave and determine the anisotropy or fractures of formation in the fi eld of acoustic logging.Based on the propagation characteristics of dipole flexural waves in cased holes,and the wavefi eld of fundamental flexural mode at three bonding conditions:good cement bonding,poorly bonded interface I,and poorly bonded interface II.The dispersion curves of flexural waves are calculated,and the eff ects of cement parameters(elastic parameters and geometric dimensions)on dispersion curves are investigated.The RAI method is used to calculate the dipole full waveforms in a cased hole with conventional or ultralight cement surrounded by a soft formation.Then,the weighted spectral semblance is used to conduct the dispersion analysis of the full waves.The numerical results show that the cutoff frequency of flexural waves exceeds the frequency band of the current dipole logging tools in the well-bonded cased hole with conventional cement in soft formations.However,when ultralight cement is used,the cutoff frequency shifts toward low values,and the ultralight cement bonding is conducive to measuring flexural waves in soft formations.When interface I is poorly bonded,the cutoff frequency shifts toward low values,and the change is evident in soft formations.The cutoff frequency in the case of ultralight cement bonding is more evident than that of conventional cement bonding.If only interface II is poorly bonded,regardless of the cement used,the cutoff frequencies are all below 2 kHz.The dipole full-wave analysis of diff erent bonding conditions further illustrates that the dispersion characteristics of flexural waves are sensitive to the cement bonding quality of cased holes.展开更多
基金partially supported by the National Natural Science Foundation of China(Nos.11204380,11374371,61102102,and 11134011)National Science and Technology Major Project(No.2011ZX05020-009)+1 种基金Petro China Innovation Foundation(No.2013D-5006-0304)Chinese Petroleum Corporation Project(Nos.2011A-3903 and 2011B-4001)
文摘Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.
基金The work is supported by National Basic Research Project No. 2001CB409709, NNSFC project (49906007, 39950001, 20177023, 40076030), CAS Innovation Project (KZCX2-206), Direct Project of CAS and Project of the Commission of Science, Shandong Province.
文摘Neomysis awatschensis was collected on the west coast of Jiaozhou Bay, Qingdao in 1992 and acclimated in the laboratory conditions. The acute toxicity method using 4~ 6 day juvenile mysid of this species is studied. The species is compared with M. bahia in taxonomy, geographic distribution, morphology, as well as the sensitivity to reference toxins. Based on the results, we recommend N. awatschensis to be a standard marine organism for toxicity test in China and the method to be applied in toxicity evaluation of drilling fluids. In this paper, we report the results of the above studies and the application of the method in the evaluation of several drilling fluid products.
文摘The finite element method was used to simulate the currents of Jiaozhou Bay and the nearcoast areas, and then established the model of the transport and diffusion of suspended particulate matter there. The transport and diffusion of dredged matter near the discharging field were estimated; and the results were used to analyze the effects of the suspended particulate matter on the marine environment.
基金supported by the National Natural Science Foundation of China(Grants 41474098 and 42074139).
文摘Crossed-dipole acoustic logging technology is mainly used to measure shear wave and determine the anisotropy or fractures of formation in the fi eld of acoustic logging.Based on the propagation characteristics of dipole flexural waves in cased holes,and the wavefi eld of fundamental flexural mode at three bonding conditions:good cement bonding,poorly bonded interface I,and poorly bonded interface II.The dispersion curves of flexural waves are calculated,and the eff ects of cement parameters(elastic parameters and geometric dimensions)on dispersion curves are investigated.The RAI method is used to calculate the dipole full waveforms in a cased hole with conventional or ultralight cement surrounded by a soft formation.Then,the weighted spectral semblance is used to conduct the dispersion analysis of the full waves.The numerical results show that the cutoff frequency of flexural waves exceeds the frequency band of the current dipole logging tools in the well-bonded cased hole with conventional cement in soft formations.However,when ultralight cement is used,the cutoff frequency shifts toward low values,and the ultralight cement bonding is conducive to measuring flexural waves in soft formations.When interface I is poorly bonded,the cutoff frequency shifts toward low values,and the change is evident in soft formations.The cutoff frequency in the case of ultralight cement bonding is more evident than that of conventional cement bonding.If only interface II is poorly bonded,regardless of the cement used,the cutoff frequencies are all below 2 kHz.The dipole full-wave analysis of diff erent bonding conditions further illustrates that the dispersion characteristics of flexural waves are sensitive to the cement bonding quality of cased holes.
