The mainly difficult problem of production inadequate return top of slurry and poor bonding cementing hole reaction are discussed in the paper; the effective factors of cementing quality – poor slurry property, lost circulation, poor displacement in long bare hole, and o8il-gas-water migration in the processes of slurry setting are analyzed; the technical countermeasure of enhancing cementing quality and preventing casing corrosive are presented. The previous troubles are solved satisfactorily and marked economic benefit abstained by using these techniques in low temperature, weak and oil-gas-water active formation.
Restricted by measuring method and accuracy,it is difficult to measure water saturation in rock porosity in Lab,the ways,such as CT,NMR are costly and not suitable to be applied frequently,After comparing resistivity logging and practical measuring data,it is found that in a certain range of concentration,there is a linear relationship between solution resistivity value and ion concentration,under the condition of reservoir,there is a linear relationship between rock resistivity value and the distance among probes,the water saturation value can be calculated by measuring the resistivity value.Research indicates in order to improve accuracy,two kinds of correcting,the relationship between solution concentration and resistivity value and the relationship between CT imaging value and resistivity value,must be carried on prior to experiment.The flooding experiment of plate model is conducted,which verifies the way can clearly reflected water-containing variation in different stage.Compared with other measuring ways,the way presented in this paper is easy to carry on and safer.
The scaling in oil well can be effectively prevented for a longer time by using solid inhibitor. To select the inhibitor component used to produce solid inhibitor, 7 types of phosphonate scale inhibitors are evaluated, and HEDP is proved to be most effective and have a rather good properity of heatstability. From the solution of HEDP, HEDP powder can be obtained by the method proposed in the paper. One method is to neutralize the solution of HEDP with a certain concentration of NaOH, then desiccate and grind the resultant. The obtained phosphonate powder is easy to dissolve in water. Another method is to add Ca(OH)2 into the solution of HEDP with a ratio of n(Ca(OH)2)/n(HEDP)=1.75. After filtration, desiccation and grinding, another king of phosphonate powder, able to dissolve slowly in water, is gotten. The elemental analysis results confirm that the main constitute of the powder is Ca2HEDP. These two types of HEDP powder can be used to prepare solid scale inhibitor by mixing with polythene.
Before the implementation of CO2 injection EOR project，screening evaluation of the candidate reservoirs can improve the success rate and economic benefits of CO2 injection. Based on CO2 miscible flooding mechanism，this paper picks out 12 reservoir parameters and fluid parameters affecting CO2 injection miscible flooding results as comprehensive evaluation parameters to screen out the candidate reservoirs. According to the investigation of a large number CO2 miscible flooding projects at home and abroad，the quantitative method is determined by theoretical analysis，field experience and probability statistics. Through calculating the combinational weight by improved AHP and entropy method and combining the advantages of TOPSIS（ Technique for Order Preference by Similarity to Ideal Solution）with gray relational analysis，the weighted GC TOPSIS model is established to screen out the candidate reservoirs. This screening method was used to assess five classical candidate reservoirs about CO2 injection miscible flooding. The results show that：by combined both subjective and objective impact， this method can correctly evaluate the potential of CO2 miscible flooding of the candidate reservoirs.
Thermal-weightlessness is utilized to determine the type boundary line and relative content of bound water on montmoril-lonite and the results of isothermal adsorption have been tom-pared. The results show that each water relative content and total water mass on hydro-montmorillonite场the method are incon-sistent to them by isothermal adsorption. Thermal weight loss a-nalysis ( 25~250`0)results show that water on hydro-mont-morillonite is free water, loose bound water and sirong bound water which respectively corresponding to the water loss in 25-75oC，75~120oC，and 120~230oC.According to thermal-weightlessness regularity(25~250oC)，it also has two clear turning points which are plp。p/ps=0.9~0.98，the two turning points are the-special humidity of clay一water system. The rela-five vapor pressure 0. 9 is the boundary line between the strong bound water and the loge bound water(osmotic bound water ) on clays, the relative vapor pressure 0. 98 is the boundary line between the loge bound water and free water on clays. The method verifies the "two special humidity" by isothermal adso p-lion and the boundary line of bound water on clays.
This paper considered the effect of formation damage and well completion methods and well completion parameters on the productivity of horizontal wells, and studied the mathematical models for the productivity prediction of the horizontal wells with open hole series of completion methods such as real open hole, slotted liner, wire wrapped screen, open hole down hole gravel pack, open hole prepacked gravel liner, perforated liner with open hole packer, perforated liner with open hole packer and external casing packer (ECP), and so on. Example calculations show that the mathematical models and their calculation methods are reasonable. They can be used to guide the optimum selection of well completion methods and the optimum design of well completion engineering.
Drill-string vibration system while is very complicated dynamic system, which has uncertain boundary conditions and randomness. Based on random signal theory, in order to quantitatively research drilling string by vibration measurement method, the article sketches out a new method——the identification of drill——string system using the cross correlation function. Using input signal, and output signal, the impulse response of drill-string is obtained. Some problems of drill engineering (critical rotation speed of frill-string, drill-string resonances, interaction between the drill string and the borehole wall and lithology of formation driied )are discussed.
Inverted pendulum drill assembly is one kind of new drill assembly for well deviation control, it displays well packed hole character under the small deviation angle and high bit pressure guards. In order to correctly use this kind of drill assembly, the authors of the article take the 311.5mm well as example to study the design approach of inverted pendulum drill assembly and provide the basis for Inverted pendulum drill assembly optimized design. Through analyzing size paring of the stabilizer above and below drill collar, as well as the different pendulum length, it is recognized that suitably increasing drill collar size above stabilizer and reducing the drill collar size below stabilizer and increasing the color length between stabilizer and bit can enhance the well deviation control ability of inverted pendulum drill assembly. When designing the inverted pendulum drill assembly, big drill bit corner should be obtained if the drill collar between bit and stabilizer don't contact the borehole wall.
Hydrogenation cracking tail oil is of excellent performance, with high saturated hydrocarbon content, low sulfer and nitrogen content, it can be ethane cracking substance, also good quality basic oil raw material of lubricating oil, it can also be used to produce transformer oil, combustion engine oil and hydraulic oil etc., meanwhile, the by product of diesel can be obtained. Hydrogenation cracking tail oil from Liaoyang petrochemical Corp. is researched in Lab, the utilization of the hydrogenation cracking tail oil as basic oil of lubricating oil is investigated through the technique of vacuum distillation, solvent dewax and replenishment refinement. Research indicates that 15.3% HVI100 basic oil recovery, 35.4% HVI150 basic oil, 20.4% HVI 400 basic oil, diesel and transformer oil, can be obtained through hydrogenation cracking tail oil.
Shale gas as an important unconventional resource，is essential for our energy security and supply，but the shale reservoir is of low porosity and extra-low permeability characteristics，and hydraulic fracturing is needed to obtain the desired economic output. We summarized the advanced technology used in American shale gas exploitation in the paper. Based on the shale gas reservoir characteristics and technology development of China，we also discussed the directions of large-scale development of shale gas in China. The results indicate that economical development of north American shale gas benefited from the advanced reservoir evaluation，horizontal drilling and hydraulic fracturing. And we also further evaluated the latest developments in north American shale gas，including reservoir evaluation，fracturing material and design optimization，production evaluation. In addition，discussion of technology adaptability and basic principles of various technologies are presented. In order to improve the development of shale gas in China，from exploration to development，we should learn from combining advanced experience with our reservoir features to carry out science and technology research，such as whole optimization of exploration and development，the volume fracturing mechanism and related technology，the evaluation of negative effects of shale gas development.
Tahe Oilfield is a carbonate reservoir with ultra-deep，ultra-heavy oil，which needs to mix with light oil. Sucker rod pumps are mainly the hydraulic feedback heavy oil pump，which is designed specifically for heavy oil production. The stress situation of hydraulic feedback heavy oil pump in mixing light oil wells was analyzed，and the sensitivity of various loading factors was evaluated，and finally we put forward that producing fluid level and viscosity of the miscible liquids are the most sensitive factors affecting the loading. On the basis of force analysis，we identify the problems of rod string designing method at present and analyze the reasons of the rupture and out of joint of the sucker sod. Through a lot of comparison of the measured and calculated data，we draw the conclusion that the stress error of optimized poles is smaller and the stress status evaluation is more accurate. The optimized calculation method will be used to calculate the maximum pump depth for various combinations of the oil extractor，rod and pump，and to guide the production management.
Four types of surfacing welding electrodes ware homemade and foundry tungsten carbide welding seam is quenched or deep cooling treated according to fragmentation, abrasion and desquamation failure form of sinteredcarbide welding layer of milling shoe. N and K model electrodes used in test is flaked likely. Thin canal cast tungsten carbide welding rod possesses the best impact abrasion resistance. The weight ratio of tungsten carbide and thin tube affects directly on peening wear resistance and peeling of tungsten carbide. The reciprocity of shadow effect of hard phase of welding seam and fasten effect of basal body and bonding phase to hard phase is the reason of strengthening impact abrasion resistance if the weight ratio of tungsten carbide and thin tube is suitable. The impact abrasion resistance of cast tungsten carbide welding layer of milling shoe increases 17.4% by quenching. It also increases 43% by cryogenic treatment after quenching. Structure analysis shows that hard phase of welding layer has little been affected by cryogenic treatment. The Structure is also η+ M6C + M23C6+ M7C3。the change of component , shape and distribution of bond phase is the main reason of enhancing impact abrasion resistance.
In the high CO2 oil and gas field operations，the applicability of rubber O-ring has a certain effect on the production safety. Previous studies related to the rubber O-ring is merely in a free state，but in the actual operating condition，the rubber O-ring is mostly in a compressive stress state. Therefore，we designed a new device for corrosion resistance and sealing property test of rubber seals in a compressive stress state，in the harsh environment with pressure of 35 MPa，temperature of 140 ℃，gas phase composition of 5%CO2 and 95%N2，and the CO2 corrosion resistance experiments on the O-rings of four kinds of rubber materials were conducted. Through comparing the mechanical properties and morphology changes before and after corrosion， the applicability evaluation of them in the above experiment environments was made. The study found that the mechanical properties of O-rings after corrosion decreased. The corrosion extent of O-rings was weaker in the compressive stress state than in the free state，and in the compressive stress state，the liquid corrosion was weaker than the gaseous corrosion，but stronger in the free state. After corrosion the swelling and aging of O-rings occurred，which caused the seal failure. The study provided references for the selection and use of rubber seals in the high temperature and high pressure oil and gas field with high CO2 content.
The application of oilfield chemicals is important to improve reservoir，enhance recovery，produce remaining oil and transport crude.In secondary recovery，tertiary recovery，fracturing and acidizing，as well as oil gathering and transportation，a lot of oilfield chemicals are used.The chemicals partially get into crude directly，and the rest interacts with reservoir，the reacted products enter crude，so there is considerable influence on following up crude oil processing.After reviewing and researching the types and components of the oilfield chemicals used in production and transportation in such western part oilfields as Karamay，Tarim，Tuha，Changqing and Qinghai，the interaction between recovery chemicals and reservoirs is studied，the existence form of the interaction products in crude oil among residual oilfield chemicals and oil production chemicals- reservoirs is identified.
This paper, based on the equivalent-depth method’s basic principle, focuses on discussing about setting up the normal compaction trend curve for carbonate rock profile, and predicts the formation pore pressure of the carbonate rock profile’s fracture-pore reservoir of Feixianguan interval on the east of SiChuan by making use of the setting up of normal compaction trend function of. The result shows the validity of the equivalent-depth method to predict the formation pore pressure of carbonate rock profile.
