Advanced Materials Research Vols. 524-527

Abstract: Based on the chemical effect of potassium silicate, gel precipitation, and the physical effect of polyols, cloud point effect, and then combining potassium silicate with polyols, a system of Potassium Silicate-Polyol Drilling Fluid with gel-cloud point effect is formed. The study shows that the mud cake is composite membrane structure in surface, including the flake membrane structure affected by potassium silicate and compactness structure affected by polyols, the flake membrane structure is with good extensibility and connectivity, and with strict and even section, membrane efficiency is over 80%, pressure bearing ability is more than 850psi, the composite membrane structure can inhibit strata hydration effectively and stabilize the shaft lining.

Abstract: The extended reach drilling (ERD) is being adopted widely in China. But it also brought a series of technical difficulties because of its own characteristics. Some progresses were made after several years of hard work in China about Hydraulics for ERD. In the paper of “Research Progresses and Perspectives of Hydraulics for Extended Reach Drilling in China, Part I”, the author demenstrated part of these progresses including cuttings transport model and precise model of pressure loss calculation. In this paper, the part of rest were presented which inlcuding hydraulic extended limit calculation model and analysis and hole cleaning monitoring method for ERD. Based on the above studies, the author finally developed a system of hole cleaning monitoring and hydraulics design and its risk analysis which could provide theoretical support and useful tool for engineering design and risk analysis before drilling. These researches are helpful to ERD and have enriched the hydraulic theory of ERD.

Abstract: The extended reach drilling (ERD) is being adopted widely as an effective and economical way of developing oilfields in China. But it also brought a series of technical difficulties because of its own characteristics. Some progresses were made after several years of hard work in China about Hydraulics for extended reach drilling, which included cuttings transport models and rules, precise model of circulating system pressure loss calculation, hole cleaning calculating models and monitoring method, hydraulic extended limit calculation model and analysis, hydraulics design and optimization method for ERD. Based on the above studies, the author finally developed a system of hole cleaning monitoring and hydraulics design and its risk analysis which could provide theoretical support and useful tool for engineering design and risk assess before drilling. These researches are helpful to ERD and have enriched the hydraulic theory of ERD. Due to space limitations, this article could only demonstrate part of these progresses, as the subtitle showed.

Abstract: The extended reach drilling (ERD) is being adopted widely in China. But it also brought a series of technical difficulties because of its own characteristics. Some progresses were made after several years of hard work in China about Hydraulics for ERD. In the paper of “Research Progresses and Perspectives of Hydraulics for Extended Reach Drilling in China, Part I” and “ Part II”, the author demenstrated part of these progresses including cuttings transport model, precise model of pressure loss calculation, hole cleaning monitoring method and hydraulic extended limit calculation model and analysis. In this paper, the rest were presented which inlcuding hydraulics design method and risk analysis system for ERD. Based on the above studies, the author finally developed a system of hole cleaning monitoring and hydraulics design and its risk analysis which could provide theoretical support and useful tool for engineering design and risk analysis before drilling. These researches are helpful to ERD and have enriched the hydraulic theory of ERD.

Abstract: Logging instrument are work in severe environment such as 140 MPa formation pressure, H2S corrosive content, 50 hours continuous working time, 175 °C ambient temperature without heat dissipation etc. The paper designed the bidirectional hydraulic control check valve which is a key control element of MDT logging instrument. And a simulation model was established based on AMESim to analyze the structure and function of the design.

Abstract: The deformation of the oil sand matrix is an important issue given that in situ and well pumping induced stresses impact on the susceptibility of the oil reservoir to produce sand. Focusing on this problem, a fully coupled seepage-deformation-damage model is developed to simulate the enhanced sand production phenomena. Finite element method with explicit and sequential iterative algorithm is used to solve the coupled governing equation system. Simulation results relating perforation cavity propagation, sand production rate and cumulative sand production are presented. The study suggests that the proposed model may be used to generate quantitative information for predicting sand production and optimizing pressure drawdown.

Abstract: Well logging interpretation is a simple and effective method to identify natural gas hydrate,because the cost of the drilling core is high and BSR technology can not be used in the permafrost zone.Establish methods of logging interpretation of gas hydrates on the basis of comprehensive analysis of geological and geographical conditions, combined with the geophysical response characteristics of the gas hydrate. Confirm the distribution of natural gas hydrate and the characteristics of distribution in Muli Coalfield under the guidance of the method. All these can provide fundamental data and scientific proof to the evaluation and target selection of the study area , and also to the discovery of natural gas hydrate in wider area of our country .

Abstract: During the process of super heavy oil exploitation in Tahe oil field, when mixing light oil, due to heavy oil and light oil entering into pump from separator directly, the existing ESP string leads to poor mixing and heavy oil coming into the pump, as a result, the pump detection period is greatly shorten; when water injection-production, the injected water can contact with electrical cable and motor directly, causing serious damage to the cable and motor, and the pump detection period is also greatly shorten. This paper designs a new type of ESP string, adding a ESP dome, a sieve tube, a mixing device, an intelligent switch and a direct flushing valve, which can improve the mixing effect of heavy oil and light oil, avoid the injected water directly contacting with electrical cable and motor, in order to protect the electrical cable and motor, improve their service life, extend the pump detection period and reduce production costs. Field test showed that the pump detection period has been prolonged after using the new ESP string, it is recommended to promote the use.

Abstract: Oil-based drilling fluids are essential for challenging drilling operations. However oil-based drilling fluid after using for the well site and the surrounding environment also poses a serious negative effect. Therefore, for studying on harmless technology of waste oil-based drilling fluid in this paper. Base on the tradition treatment technology for waste oil-based drilling fluid, by the preferred for treatment chemicals, improved the experimental methods and conditions, achieved some research results. Added 8.5g/L xylene/ispropanol complex demulsifier under the 50°C, pH value of 4 conditions to breaking the waste oil-based drilling fluid, the remove base oil rate is 84%, the moisture content is less than 1%, reached the "Twelfth Five-Year" major projects of national requirements' indicators; added 11ml/100g breaker SW-B, 10g/100g lime and 30g/100g cement to system for curing the waste drilling fluid, the solidified strength of the cured than 0.5MPa; Determined to leaching toxicity of solid waste, the pollution index of leaching toxicity of solid waste meeting National Integrated wastewater discharge standard (GB8978-1996).

Abstract: In the low permeability reservoirs development process, some times horizontal well is not meet the anticipant production for low vertical permeability or serious reservoir damage, so the horizontal well fracture is needed to improve production rate, several fractures would be created along the length of horizontal well to get the more production rate and ultimate recovery. The fracture shapes was introduced, the principle, characteristics and treatment steps of different Multi-interval fracturing technique was analyzed such as chemical isolation, mechanical isolation, hydraulic sand blast, and limited entry fracturing technology, the feature of limited entry treatment and staged fracturing treatment were discussed for providing some suggestion to field fracturing technology choosing.