Advanced Materials Research Vols. 962-965

Abstract: The northwestern margin of Junggar Basin is one of the most prolific petroliferous areas in Junggar Basin. While there exists many drilling problems, such as poor drillability, low drilling penetration rate (ROP) and long drilling cycle time due to the complex lithology and pressure system in low formation, big pressure change, several sets of coexisted formation pressure system of northwestern margin. In order to improve ROP, make better use of resources and solve these drilling problems, utilizing the TorkBuster Torsion Compactor (TorkBuster) with personalized PDC bit has been introduced in the northwestern margin. This paper presented the workings, technology characteristics and experimental application of TorkBuster in Ma13(M) well areas. The application results showed that the speedup effect of this drilling tool was obvious and drilling cycle time was shortened substantially. The technology has provided a fast and effective drilling method for Karamay Formation and Wuerhe Formation of Triassic in northwestern margin of Junggar Basin.

Abstract: Fergana Basin, Central Asia's oldest oil and gas exploration area, reached an output of approximately 1.5 million tons per year in 1950s.^【1,2】. Even after years of exploration and development, there is still a great resource potential^【3】The exploration of block A in the south of the Fergana basin was started in 1930s suspended when the USSR collapsed. It was resumed in 2011 after it was acquired by company Z. There are some problems for the log interpretation such as the lack of related data, the low formation pressure caused by excessive exploration,. These problems cause the decline in terms of similarity between the log interpretation and the testing data. Based on the above issues, this paper studies the analysis of the problems and put forward reasonable proposals to the next step of the work to provide a sound basis for further exploration.

Abstract: In view of oil-water two phase displacement experiment can't from the micro level such as throat problem for reservoir use condition is described,Using nuclear magnetic resonance (NMR) technology can reflect the oil-water distribution from the microscopic view, Combined the macro oil displacement effect and micro pore structure. By using nuclear magnetic resonance T2 spectrum changing into throat radius and saturation calculation method in different throat range. Quantitative description the distribution of bound water, residual oil I and oil produced in different in pores of drainage and Suction process, to a certain extent in the comprehensive understanding of microscopic reservoir pore space, has the vital significance for reservoir evaluation.

Abstract: The CO₂/H₂S corrosion behaviors of oil tube steels N80 and P110 at different CO₂ partial pressure (45psi, 135psi, 225psi, 315psi) were investigated by corrosion tests, corrosion rate calculation and corrosion morphology observation. The results show that at different CO₂ partial pressure, super-serious CO₂/H₂S corrosion occurs on steel N80 and steel P110. With the increase of CO₂ partial pressure, the CO₂/H₂S corrosion rates of both steels increase gradually.

Abstract: Using acoustic emission (AE) technique, test the blowout preventer (BOP) shell with a crack in the pressing process. Firstly, cut a notch of 100mm long and 5mm wide on a BOP shell and weld partly, then pressurized by pneumatic pumps. Test the BOP shell during the crack propagation by AE. The result showed that the AE technique can reflect the activities of the defects timely and effectively, and the destroy situation of the blowout preventer shell in the process of pressured and the location was accurate.

Abstract: The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. This paper utilize the ANSYS finite element program to simulate the 3D model of borehole and hole wall to calculate the freezing radius of the steady state, heat loss, temperature of the freezing point and the conductive heat time of the unsteady state. And this study has provided the basis of the freezing technology for borehole stability of gas drilling.

Abstract: The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. This technology could achieve the purpose of strengthening the formation and reducing the fluid flow of the formation, and it greatly broadens the scope of application of gas drilling.

Abstract: Layer steam injection is a most effective method in heavy oil recovery. Layer Steam Injection Simulation Test System is a simulation test system of layer steam injection. It had been independent developed based on technologies such as PC, modern sensor, automatic control etc., so that to solve experimental problems like doing layer steam injection, selecting and testing downhole tools exactly. The system can offer no less than 320°C and 17MPa experimental environment. The system use heat transfer oil instead of high temperature and high pressure steam to do the experiment, which is a new way to do the similar experiment; the measurement and control system were designed and developed to control the whole system and measure the flow, pressure and temperature. It is determined that system can meet the design in advance through analysis of experimental data.

Abstract: Imbibition oil recovery theory main includes capillary forces theory, wettability alteration theory, ion desorption and flow theory. Imbibition is effected by many factors, including the reservoir rock wettability, reservoir properties, fluid properties and environmental factors. Due to the complexity of effect factors, the scholars’ views are not consistent on the imbibition oil recovery theory. In this review, the influencing factors and relationship of imbibition oil recovery theory are presented and comparatively discussed. Furthermore, the latest experimental research methods and progress are introduced as well. At last, the future development of the theory and the problems to be solved are predicted.

Abstract: During well testing, liquid pressures exerted on testing string change frequently. Actions of downhole tools rely on annular or tubing pressure operation; information collection of the reservoir needs the production control valve switch on and off repeatedly. Pressure variability makes it very difficult to predict testing string safety both in deformation and strength. Although many measures have been taken to forecast pressure and component of the reservoir, exceptions often occur, and one exception is abnormal pressure. Considering technological process, axial deformation, helical buckling and strength of testing string are calculated with abnormal high and low formation pressure. Influence of other parameters is discussed, including string structure, completion fluid density, cushion and downhole tool operation pressures.