Abstract:PDC bits have greatly changed the oil and gas drilling since their introduction in 1973. But PDC bits grew slowly in early about 15 years. Then their growth sped up obviously for innovations and improvements, such as Layered diamond table、NPI patents、Cobalt leaching、 Anti-whirl、 Hydraulics design, Computer Modeling etc. At present，PDC bits drill 90% of worldwide footage. In recent years, NOV has launched 4 types of Helios PDC cutters, which could increase the thermal stability、abrasion resistance、 impact toughness and steerability of PDC bits. Those bits are suitable for drilling hard、abrasive formations, as well as some difficult-to-drill formations with high ROP and durability. Applications were successful in Norway、Middle East、Australia、US Texas etc. ONYX 360° rolling PDC cutter，launched by Schlumberger, which keeps the cutter’s edge sharp and relatively cool, prolonging cutter life and overall bit durability. Applications in many oil and gas field showed that the average ROP of the bits with rolling PDC cutters increased more 40% compared with the bits installed by fixed cutters. The rolling cutter’s bits also increased footage 40%～70% compared with the fixed cutter’s bits.

Abstract:Ruoergai uranium deposit is one of the four basic types of uranium ore fields in China, the formations are limestone and silicon limestone with the development of groups longitudinal fissures. There was no mud return while drilling in such kind of formation because of the total lost circulation. It was very difficult to maintain mud properties and borehole stability and a lot of manpower and material resources were spent on this. Based on the analysis on the mechanism of lost circulation, a technical measure was put forward. The basic idea is to reduce leakage pressure for balanced drilling. The research and experiments were carried out on air bubbles mud, micro-bubble mud and cenospheres mud systems. The practice shows that the cenospheres low-density mud system is suitable for drilling operation in Ruoergai uranium ore field.

Abstract:By comparing and analyzing the conventional project of sidetracking slim-hole horizontal well and considering the rig ability, this paper puts forward an offshore drilling and completion technology of efficient sidetracking slim-hole horizontal well, including the slim-hole horizontal well drilling, sand control methods optimization and oil-water layer packer. By the application of drilling and completion in 4 adjustment wells in QHD32-6F platform, it shows that with this technology, the operation difficulty can be effectively reduced for small size casing sidetracking and the comprehensive cost of drilling and completion can be greatly reduced. The broad application prospect of this technology is presented.

Abstract:In view of the important significance of the study on oil shale in-situ fragmentation for improving the heat transfer efficiency, an indoor research method of oil shale fragmentation was put forward, namely freezing-thawing cycle method. The experimental mechanism, experiment table design, sample preparation, experimental data acquisition and analysis etc. were discussed in this paper. The freezing-thawing cycle experiment was carried out on oil shale crack propagation in single hole mainly by engineering simulation. According to the design requirements, 2 groups of specimen were prepared and the experiment table was established. Simultaneously, the used oil shale samples in each experiment stage were detected by ultrasonic detection method, which provides a feasible experiment scheme for oil shale in-situ fragmentation research and can be taken as reference to the heat transfer efficiency of oil shale research.

Abstract:This paper presents a relevance vector machine based on particle swarm optimization method (PSO-RVM) for assessing the drillability of rock formations. Five parameters, including the depth of rock formations (H), acoustic travel time (AC), electrical resistivity (ρd), density of rock formations (ρ) and the shaliness of rock formations(Vsh), are selected as the basic parameters in the PSO-RVM model. The Du4 well drilling in an oil field is chosen as an example and the PSO-RVM method, multiple regression method and relevance vector machine (RVM) method are used to assess the rock formation drillability of the well. The results suggest that the predict results of PSO-RVM method accord well with the measured data and the prediction accuracy is significantly higher than that of multiple regression method and the RVM method. It is shown that PSO-RVM method can be applied in the prediction of rock formation drillability with its advantages and high accuracy.

Abstract:This study has tried to improve lubricating properties of water-based drilling fluid with adding nano oxide particles to it. Alumina (Al2O3), titania (TiO2) and silica (SiO2) nanoparticles were selected as modified drilling fluid additives, the study was made on the effects of adding different kinds and concentrations of oxide nanoparticles on lubricating properties and friction reducing of water-based drilling fluid by using the extreme pressure lubrication device and the pin-on-disk friction and wear tester. The results show that the three kinds of spherical nanoparticles all have the effect of lubrication and antifriction, but the drilling fluid containing SiO2 particles has the best properties of lubrication, filtration and antifriction. When the adding amount of SiO2 nanoparticles was 0.4%, the filtration was minimum, the reduction rates of lubricating and friction coefficients were 15.6% and 32.0% respectively with smooth wear scar, the friction reducing effects was the most evident. When the concentration of the nanoparticles was higher than 0.5%, the friction reducing effect decreased with obvious delamination and wear.

Abstract:According to the characteristics of low bottom hole temperature, serious leakage and poor sealing effect by conventional plugging materials and methods for loess layer leakage in Yanchang oilfield, PLC cross-linked polymer gel was developed, which could realize rapid cross-linking in low temperature. Taking polymer gel solution with a concentration of 6.5% and organic compound cross-linking stabilizing agent with a concentration of 2%, according to the cross-linking ratio of 10∶1.3, the rapid gelling test was made under the temperature of 17.6℃～40℃. The test results show that PLC cross-linked polymer gel has the characteristics of rapid gelling, strong anti-pollution ability and good compatibility with bridging material, the match usage of polymer gel solution and organic compound cross-linking stabilizing agent has good application prospects for plugging leakage in loess layer

Abstract:Because of the high drilling capacity of the drill configured for small diameter deep hole diamond drilling, with the high rotation rate and drilling efficiency in the hole sections of medium-depth as well as the less, serious bit burning accidents, diamond bit (core barrel) and rocks sintering, are often caused by the changes of working condition or a certain drilling parameter. With the case of serious bit burning accident, the paper analyzes the working conditions in medium-depth hole section of diamond drilling, there serious bit burning accident is easily happen and discusses the key issues of prevention and treatment of the accidents.

Abstract:As an advanced technology in ultra-heavy oil reservoirs development, SAGD drilling technology has been used in large scale both in China and abroad. Pilot test area was set up by Xinjiang Oilfield Company in 2008 and SAGD technology was tried for ultra-heavy oil reservoirs development in Zhong18 well area of Fengcheng oilfield with definite benefits. Based on the recent construction cases of horizontal producing well FHW117P and horizontal steam injection well FHW117I, the paper introduces the dual horizontal well drilling technology for SAGD. Tower type packed hole anti-deflection tool, magnetic orientation technology and specific drilling fluid technology were the key in the dual horizontal well drilling construction, through keeping lubricity of drilling fluid and putting downforce on screen pipe by circulative pressure device and large-weight drill collar, φ1778mm screen pipe was smoothly lowered into φ2159mm borehole.

Abstract:Adjustment well is used to improve the production and change the relationship between the injection and production wells. Slot is the most important limiting factor for adjustment wells. But because of the small design area for offshore oil and gas development platform, dedicated area for well slots becomes even smaller, eventually leading to reduction of the number of well slots. Taking S platform as an example, this article presents two layers of casing of φ3397mm and φ2245mm in diameter respectively, cutting technology was used in the large-sized slot with full annular cementing, and the twinhole-in-monobore was completed in the abandoned slot.

Abstract:To promote the scientific of drilling work and achieve the continuous monitoring of drilling process and accomplish the forecast of the hole abnormal conditions, drill field digital information collection and transmission system matched with XY-8 drill was developed by combining electronic technology, computer technology, communication technology and drilling technology to realize collection, processing, storage and remote transmission of drilling parameters, as well as the forecast of the hole abnormal conditions, remote management of drilling site can be operated by video transmission. This system has been applied in Lingbao of Henan Province with good economic benefit. The paper briefly introduces this system about its composition, function, features, the principle of parameter detection, system software and production applications.

Abstract:Marine sediment stratum is mainly composed of silt, soft soil, semi-concreted mudstone and sandstone, the sediment stratum sampling is an important part of marine engineering and geological survey. The original state of sample is easy to be disturbed by the use of conventional rotary sampler with low sampling rate; while by static pressure sampler, the sampling rate is not ideal in sandstone and semi-concreted mudstone. According to the above situation, combining the characteristics of static pressure sampler and hammering sampler, an impact telescopic wire-line coring sampler was developed to realize truly-preserving sampling in submarine sedimentary bed mainly consisting of sediments.

Abstract:Hydraulic plug for water pressure test is more reliable and flexible than other types of plugs, but difficult drainage and pressure relief after the test have been remained, so its usage is confined to shallow holes or holes with high water levels. This problem was studied and the solution was put forward. New type of hydraulic plug structure was designed for drainage and pressure relief of hydraulic plug, by which the limit of hole depth is broke through and the hydraulic plug can be widely used. The paper introduces this new hydraulic plug about its structure, working principle and engineering application effect.

Abstract:Core orientation technology is an engineering method, by which original ore bed occurrence can be directly and accurately obtained. Reflex ACT series core orientation device produced by Reflex Company of Australia are introduced in this paper about its structures, technical parameters, operation process of core orientation technology. Good results had been achieved since Reflex ACT series core orientation device was applied in Tanjianshan gold mine of Qinghai Province, the experience and the understanding in the advice application are summarized.

Abstract:Through the testing examples of uplift piles for deep excavation bracing in the complex formation of coastal area, the test parameters and methods are introduced, as well as the uplift pile construction technology of deep excavation bracing, such as boring technology in rockfill formation with soil, core sample taking at the end of pile and pile hole cleaning. The test data show that the test parameters of uplift are reliable and can meet the requirements of float resisting capability of the structure design, which provides the data support for the application of uplift pile in deep excavation.

Abstract:To improve the freezing ability of single pipe of existing freezing pipe for the situation of circulation refrigerant medium dosage and construction power consumption. The traditional circular section of freezing pipe may be designed into special-shaped ones. The paper briefly introduces the freezing pipe with X-shaped section and made the study on the change rule of temperature field while freezing pipe with X-shaped section being frozen by finite element software. At the same time, by the comparative analysis on the temperature fields of circular-shaped, square-shaped, I-shaped, T-shaped and Y- shaped single pipes, the conclusion was drawn that although the sections of X-shaped and other shapes of freezing pipes are noncircular, the temperature of frozen soil is concentric mode distribution with freezing pipe as the center, the nearer to the freezing pipe is, the lower the temperature. While being frozen 20, 30 and 40 days, the radius of -10℃ circular frozen wall were to 200mm, 240mm and 300mm respectively around X-shaped freezing pipe. Compared with circular freezing pipe, the special-shaped ones have advantages of greatly reducing construction electricity comsumption.

Abstract:This paper introduces the mechanism, process, key construction points and construction machinery as well as main parameters in large area, large depth and heavy contaminated site management by high pressure rotary jet grouting and deep mixing methods. The engineering practice proved that these two geotechnical construction technologies have advantages of high quality, good effect, short duration and low investment. The existing problems in the construction were analyzed with suggestions for further study.

Abstract:Drilling industry experienced 10 years of prosperity and developed too rapid affected by the market; the management was ignored in the pursuit of production efficiency. Now, facing to the small market share, low price, high cost and great pressure of competition, how to survive and keep on developing must be solved for drilling industry. Through the analysis on the current situation of the development of drilling industry, the paper exposes some problems in drilling cost management, summarizes the characteristics of cost management in drilling industry and discusses the measures for the implementation of scientific management of machines production by means of project cost management with practical examples as well as qualitative and quantitative analysis on machine production.