Sun, Hehui (No.1 Mudlogging Company, BHDC, CNPC) | Lao, Liyun (SWEE school, Cranfield University) | Li, Dengyue (No.1 Mudlogging Company, BHDC, CNPC) | Tao, Qinglong (No.1 Mudlogging Company, BHDC, CNPC) | Ma, Hong (No.1 Mudlogging Company, BHDC, CNPC) | Li, Huaiyu (No.1 Mudlogging Company, BHDC, CNPC) | Song, Changhong (No.1 Mudlogging Company, BHDC, CNPC)
More and more early kick/loss detection (EKLD) devices are being used in drilling operations, whether in the field of onshore or offshore drilling. In the field of deepwater and offshore drilling, high-precision electromagnetic flowmeters and Coriolis flowmeters was used to measure the inlet and outlet flow rates of drilling fluids. Good effect was achieved, but are affected by drilling fluids, space limitation of the wellsite and production costs when in the field of shore drilling, engineers usually use the paddle- flowmeter and ultrasonic liquid level meter to measure the inlet and outlet flow. It exists the problem of low measurement accuracy and prolonged warning time. In order to improve the accuracy of measurement and the accuracy of early warning, the electromagnetic flowmeter has been studied in terms of flow measurement at the outlet of on-shore drilling. The study found that the installation position of the electromagnetic flowmeter in the V-shaped test pipeline is a key factor that determines the accuracy of measurements. The influence of different fluid types on the measurement was studied by fluid dynamics. The fluid model was established using Ansys fluent software, and the boundary conditions were set in conjunction with the relevant parameters of the drilling fluid. It was found that the descending segment of the V-shaped pipeline was suitable in the state of laminar and dispersed flow. It is an appropriate mounting position for the electric flow meter; for the slug flow, the rising section is a suitable installation position. The theoretical conclusion is verified by laboratory simulation and field tests. The results of theoretical research were used to optimize the design of the test pipeline, and the problems of transient large flow passage and solid-phase debris deposition in the field were solved, and good results were achieved. An automatic grouting module was developed based on the accurate measured outlet flow data. The automatic grouting operation is very helpful for the construction process of drilling and triping, improved the safety level of well control, and laid a good foundation for the large-scale application of EKLD devices in the field of shore drilling.
Li, Guanghuan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Ma, Hong (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Long, Tao (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Huang, Daquan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Tian, Zengyan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Zhang, Aishun (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Wang, Weizhong (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Hou, Shili (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Gong, Chunwu (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.)
Oily cuttings are hazardous wastes containing oil, hydrocarbons and heavy metals, which generate a significant risk to human and enviroment without appropriate treatment. The common treatment, including heating, burning, microbiological degradation and so on, are not fast and effective enough to solve the pollution problem caused by oily cuttings. This article provides a method with higher efficiency and lower cost. An intelligent cleaning agent, synthesized for cleaning oily cuttings, is easy to dissolve in water and makes oil and water easily emulsify during cleaning process, so as to achieve the purpose of removing oil. By adjusting the pH, the emulsion will be automatically demulsified after statis, and then the oil and water are separated from each other, which simplify the progress of treatment. Ultrasonic technology is assisted to clean the oily cuttings, which effectively reduces the amount of cleaning agent and increases the treating efficiency of the cleaning agent. In this paper, the effects of the cleaning agent dosage, heating temperature and ultrasonic time on the deoiling ratio are analyzed. The oil recovery rate is above 90% with the dosage of 7.5g/L oil cleaning agent under the 55 °C and 10 minutes. The recovered oil has good quality and meets the demand for preparation of oil-based drilling fluid. The residual wastewater, including the cleaning agent, can be reused as cleaning liquid by adjusting the pH to neutral and adding fresh cleaning agent. This technique improves the treating efficiency of oily cutting and greatly lower the cost, which would have a high value to popularize.
Numerical simulation method is applied to study the effects of some parameters on steam overriding, including oil layer thickness, crude viscosity, vertical/horizontal permeability ratio, perforation method, etc. Therefore, the change pattern of steam overriding is obtained and the technical conditions for steam overriding are pointed out. Field test results indicate that by taking some measures, such as adopting the "uphole?? perforation, profile control, separate or selective steam injection, vertical and horizontal well combined SAGD, etc., the uneven producing of the reservoir vertically due to steam overriding can be further decreased. Moreover, these measures play an important role in increasing oil recovery ration during the later production period of CSS. The successful application of these techniques will provide theoretical support and technical guarantee for the production of similar super heavy oil reservoirs in the world during the later production period of CSS.
Keywords: Steam overlay; CSS; Separate or selective steam injection; Vertical and horizontal well combined SAGD