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Puguang gas field is the first deeply buried formation and high-sulfur natural gas field on developing. Due to the special composition of natural gas, the deliverability evaluation has a lot of problems. So it is very difficult to conduct a deliverability evaluation with the pressure of well bottom. In this study, an equation of wellhead deliverability is established by testing data. And it is evaluated through the wellhead open flow potential and absolutely open flow potential which is determined by another deliverability equation from well testing data. Results show that there exists a good linear correlation between wellhead open flow potential and absolutely open flow potential in each well of Puguang gas field. In addition, through applying this correlation, absolutely open flow potential can be calculated through wellhead deliverability equation, which provides a new method to study deliverability.

The purpose of frac fluid flowback is to outflow the fracturing fluid and prevent the proppant backflow, which determines the effect of fracturing fluid flowback. The fracturing treatment in field lacks relevant theoretical models for prediction. Therefore, this work focuses on establishing the flowback model of hydraulic fracturing for multilayer fractured wells. Then the wellhead pressure and fluid flowback volume are predicted based on the actual parameters of fracturing treatment in the process of flowback and are compared with the field data of frac fluid flowback. Results show that the wellhead pressure and fluid flowback volume calculated by the model are consistent with the field data. The sand production ratio of the three wells during the flowback process is lower than 1% indicating that the optimized parameters achieve the purpose of flowback operations and reduce the flowback volume of the proppant.

Sebei NO.2 gas field I-1 layer group is shallow-buried with comparatively lower formation energy. In the process of developing, the formation pressure drops and the total energy consumption of the gas-liquid two phase pipe flowing increases gradually, which leads wellbore to produce accumulated fluid that greatly reduces gas well productivity. This paper is based on the mastery of gas field reservoir characteristics and production dynamics, analyzing the changes of gas well production performance before and after gas wells with accumulated fluid. A wellbore liquid loading identification model of Sebei NO.2 gas field is established in terms of the liquid removing capacity calculations, wellhead characteristic observation method, the pressure gradient method. In the aspect of liquid loading volume, the study based on the theory of wellbore gas-liquid two phase flow, using four classical pressure distribution models to construct a combined model that is more suitable for single wells, analyzed the features of fluid gas well distribution with structural characteristics and other aspects. Practical application shows that the analysis results are reliable and highly practical, and deepening the understanding of the phenomenon of gas liquid loading.

The phenomenon of hydrate freeze-plugging is very widespread in Jilin oilfield M gas field exploitation. Freeze-plugging tends to occur in winter, mainly including ground pipeline, wellhead and wellbore freeze-plugging, etc, which affects the normal production of gas well, also has restricted the gas reservoir development and will cause huge economic losses. In order to prevent the freeze-plugging occurred in gas well, methyl alcohol is used to inject into single well at the rate of 600 to 3080 L/day. The field condition shows that the result of injecting methanol is not obvious, besides, the toxicity of methanol and its high cost already cannot satisfy the oilfield actual demand. Therefore, we need to research and develop new hydrate inhibitors with low cost and high efficiency to solve the problem of freeze-plugging.

The dynamic response of the casing string under the mud line is concerned by engineer when deepwater drilling operating. Considering with the nonlinear characteristics of seabed soil, a dynamic differential equation of the casing string below mud line was established. Then the Newmark method was adapted to solving this equation by time step. Results illustrate that, the deformation and internal force of the casing string in low frequency region have little difference with the static situation. The amplitude of the string displacement increases gradually at the natural frequency. And the hysteretic phenomenon more and more obviously at this point also. In general, there are almost no influences to the dynamic lateral bearing of the casing string when not considering the wellhead vertical force. Use a static method to analyses the wellhead stability and the string bearing capacity can meet the project requirement. The dynamic analysis of casing string coupled with the marine riser is very necessary to future work.

In the later period of water distribution to increase output of oilfield, it is difficult for the measuring and adjusting apparatus going down in the lubricator when the wellhead pressure reaches to some value, in separate zone injection testing. For this reason, we analyzed its reasons through theoretical derivation and experiments. According to the basic theory of statics of fluid mechanics, we derive and set the mathematical model among the static pressure differential of measuring and adjusting apparatus and the main factors such as wellhead pressure, cable diameter, etc. Indoor experiments and field testing jointly, we set the relationship of wellhead pressure affect the friction between the packing and the cables. The result: down resistance of measuring and adjusting apparatus in lubricator is linear with wellhead pressure and it is square with cable diameter, friction force between the packing and the cables have no big change while the wellhead pressure changes. Through the study of firing resistance, we can calculate the additional weight needed accurately when measuring and adjusting apparatus in lubricator fire and down, and provide theoretical basis for optimizing running parameters and heightening testing efficiency.

With the exploitation of Jingbian Gas Field for decades, the formation energy gradually decreasing, and the wellhead pressure of some gas wells were found approaching to the pressure of gathering pipe network. Furthermore, some wellhead pressure can not make the produced natural gas get into the gathering pipe network. S well block of Jingbian Gas Field was set as the research object, applied numerical simulation method to create a new three dimensional geological model for gas reservoir of S well block, and then matched the reserves of gas reservoir and productivity parameters of gas well; applied the orthogonal test method design a variety of charging scheme and simulated every scheme; finally, decided an applicative pressurization scheme for gas well of S well block in Jingbian Gas Field.

The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO2 .The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO2 composite displacement experiment and 4 group double tube surfactant adjustable profile + steam +CO2 composite displacement experiment. And record after steamflooding steam drive with carbon dioxide and surfactant improvement value. The results show that in the steam composite flooding, enhanced oil recovery rate increases as the number of composite plug PV growing. Carbon dioxide and steam are injecter by 1:1 alternately and composite plug is 0.3PV, in which enhanced oil recovery rate can reach 19% and cost of oil displacement agent is 38.77 Yuan/ton of oil. Carbon dioxide and II thermostability discharge aiding agent are injecter by 1:1 alternately and thebest composite slug is 0.3PV, in which enhanced oil recovery rate can reach 23.7% and cost of oil displacement agent is 289.66 Yuan/ton of oil. When the plug PV number is same(0.3), surfactant + CO2 composite plug can improve more 4.7% than steam +CO2. Hence, thermostability discharge aiding agent have some effects on improving recovery.

Air volume control at wellhead is inconvenience when conduct fan performance test for metal mine We use total return air roadway to adjust conditions, testing air volume at main fan diffuser ,which has advantages with simple operation, security, ventilation recovery fast and so on and test out surface air leakage drag masterly. By analysising the testing process, point out precautions advantages and disadvantages of such test methods which have certain reference value for related test.

SAGD technology is utilized to exploit heavy oil in Du 84 block Shu 1 area of Liaohe Oilfield, the temperature of wellhead produced fluid can reach up to 170-180°C. To avoid wasting the thermal energy, a set of scheme of cascade utilization of waste heat was proposed to combine the generation of electrical energy and heating in this paper. The generating capacity, heating area and its economic efficiency are calculated and analyzed in this scheme. In addition, taking the annual total cost of the condenser as the objective function, the parameters of the condenser are optimized by using optimal function in MATLAB software. The results can be used to conduct the design of the waste heat utilization system in practical project. Keywords-; Energy saving; optimal design; low temperature waste heat; SAGD

Righting manipulator is imitating the shape of the hand, to replace the worker in the wellhead operations crawl and righting columns action, implemented in unmanned condition wellhead mechanical pipe string centering automatically to a predetermined location function This review focuses on remote control wellhead operations structural design of the righting manipulator, theoretical research, virtual simulation and functional experimental studies.

For oil well, material analysis on oil well wellhead assembly is an important factor of oil production system life. In order to ensure the long-term development of oil wells, this paper mainly introduces the the material analysis on oil well wellhead assembly,such as material analysis for environment-assisted fracture and stress corrosion on wellhead assembly, requirements for materials of oil well Christmas Tree and tubinghead and so on. By taking T1 well as an example, this paper optimizes the material selection of well wellhead assembly for T1 well. For application, the technology above has a good practicality.

For natural gas well, material selection of gas-well wellhead assembly is an important factor of gas production system life. In order to ensure the long-term development of gas wells, this paper mainly introduces the material selection of gas-well wellhead assembly, proposes the optimization idea and technique of gas-well wellhead assembly. By taking W well as an example, this paper optimizes the material selection of gas-well wellhead assembly for W well. For application, the optimal materials of gas-well wellhead assembly in W well have good performance of corrosion resistance.

Presently, rescue equipment and method for uncontrolled blowout in offshore drilling are very rare, of which the consequences were very serious. With analysis of mechanics of materials based on shut-in water hammer pressure and wellhead pressure while rescuing, and fluid mechanics of uncontrolled blowout based CFD, a rescue equipment for uncontrolled blowout in offshore drilling has been invented, and proposing a rescue method. There are several emergency scenarios have been made. Take the “deep horizon oil rig” in the gulf of Mexico for example, the flow field properties around this equipment could be calculated by software to prove the reliability of it. The equipment is a conceptual invention which could be designed in different types according to the size and strength of original wellhead. This equipment could prevent well blowout and collect leaped oil.

Geothermal resources can not be ignored in the new century energy, Through the relevant formula in combination with the actual situation of the Liaohe Basin, by the predication of single well production and well head temperature, Find favorable areas that single well production and wellhead temperature both high. These areas are considered favorable areas for geothermal resources in Liaohe Basin. We carry out comprehensive evaluation of geothermal resources in Liaohe Basin. Finally, the total amount of geothermal resources, the total amount of geothermal water and recoverable geothermal resources in Liaohe Basin were determined and the favorable area for geothermal resources is divided, the total amount of geothermal resources, the total amount of geothermal water and recoverable geothermal resources the favorable area for geothermal resources were predicted.These results provide guarantee for the future exploration and development of geothermal resources.

As a key datum in the petrochemical industry, Water content ratio plays an important role in dehydration, storage selling and petroleum refining. According to the oil well production site, this thesis is based on the oil-water mixture’s density to calculate the water-rate in petroleum, carried on the error analysis to this measuring method, and assessed the scope which this metering equipment is suitable. The wellhead drop back pressure device is effective in monitoring oil wells, to achieve the single well production of display, and when the single well is not working properly, you can discover and resolve problems. The system features are simple structure, easy to carry, stability of Measurement and easy maintenance.

Fracturing flowback rate is one of the most important parameters to evaluate fracturing effects. While calculation of fracturing flowback rate is always lack of theoretical model to predict, it is always been solved by accumulation of filed fluid after fracturing finished in oil filed. In order to tackle this problem, a great deal of work has been done to establish a model for solving fracturing flowback rate, in which procedures like fracture closing, fluid loss, formation fluid flows and well bore flow are entirely considered. Based on comprehensive procedures, a few functions are established in this model. The average fracture pressure was calculated by adjusting time that might affect fracture closure degrees. According to wellhead pressure, bottom hole flowing pressure and average fracture pressure which was used to calculate flowback quantity leaded by fracture closure were achieved. Besides, total time that fracture was entirely closed was also achieved after fracture being fully closed, flowback quantity consisted of two parts, fracture and formation. In addition, the model was solved through finite difference method and simulated by Matlab. In comparison with the target result, fracturing flowback rate, the modeling results, are almost identical with that of conventional methods. Therefore, this model can be taken as a reliable theoretical guidance to predict fracturing flowback rate in oil flied.

To get working loads for analysis of strength safety of well testing tubing strings, providing references to combine tubing strings and select operation parameters, the working loads of tubing string were measured by self-made load measurement device for down-hole tubular strings and the stresses of tubing strings with measured load were analyzed with ANSYS. The dynamic response and strength of tubing strings exerted by varied pressures and weight were analyzed, taking wellhead and packer as fixed constraints. It was found that the maximum stress would vary sharply around the baseline with radial acceleration and increase as much as 37% if the acceleration is 0.38g

To solve the single tube gathering process paraffin oil viscosity reduction shaft and gathering the problem of high back pressure. Technical application of crude oil pour point depressant, mixed ester, benzene, ethylene oxide such as octylphenol ether compound by an oil-soluble DRA. Dosage in the 50 ~ 100mg/l to meet the water when the wellbore is less than 25% of the wax viscosity and single-tube process requirements gathering, can be compared to the multi-port wells, monitoring data before and after dosing showed that the crude oil after dosing freezing point decreased 5.6 °C, the average rate of 87.4% viscosity reduction, the average rate of 91.5% paraffin. Pipeline wellhead back pressure reduced by 20 to 30 percentage points

With the continuous development, the gas well productivity will decrease. The deliverability test can be used to evaluate gas well productivity, but this method always needs long test which will affect daily production seriously, especially for low permeability gas wells, also there always isn’t enough data in the field. Aiming at this problem, this article presents a new real time method to get the gas well productivity. This new method avoids deliverability test and only needs daily production and wellhead pressure data, so the analysis process is easy and this method has strong practicality. It is proved that this new method works well in the field case.

The problem facing of spool used in high pressure wellhead is illustrated. The methods and steps of conventional design and autofrettage design for spool are introduced. Based on the 4rd strength theory, the wall thickness of spool under 103.5MPa is designed using the two methods. Compared with the conventional design, the wall thickness of spool is declined 16.6%, the gross weight is 60% of previous, the stress distribution is more uniform and the utilization rate of raw materials is increased by autofrettage. Thus it provides a theoretical basis for design of spool used in high pressure wellhead.

The crude oil in Kuidong region of Liaohe Tanhai Oilfield is characterized by high oil viscosity, high density, high content of colloid asphalt, low content of wax and low freezing point. In the shallow region, the large current, high content of silt, long-distance subsea buried pipeline and drift ice in winter have brought great challenge to offshore construction and oil-gas transportation. In this paper, the investigations of offshore construction project and platform process are shown. Based on the well production rate, gas-oil ratio, water cut, wellhead back pressure and outlet temperature, the range of daily transportation volume was acquired, as well as the maximum inlet pressure and pressure difference of the pump. The paper also selected technically and economically feasible pumps, then designed the public projects, corresponding electric power and self-control facilities. The selected skidded twin screw multiphase pump system can smoothly transport produced liquid to the terminal systems onshore without any effect on the daily output.

The problem facing of spool used in high pressure wellhead is illustrated. The methods and steps of conventional design and autofrettage design for spool are introduced. Based on the 4rd strength theory, the wall thickness of spool under 103.5MPa is designed using the two methods. Compared with the conventional design, the wall thickness of spool is declined 16.6%, the gross weight is 60% of previous, the stress distribution is more uniform and the utilization rate of raw materials is increased by autofrettage. Thus it provides a theoretical basis for design of spool used in high pressure wellhead.

It’s difficult to measure bottom pressure in the fractured-vuggy reservoir, and measuring cost is usually high; In this paper, using the modified Beggs-Brill method, the variety of wellbore pressure has been calculated and analyzed. Results show that the variety of wellhead pressure is consistent with that of bottom pressure, and the variety of wellhead pressure is greater than that of bottom pressure. Thereby a simple method of predicting bottom pressure through wellhead pressure is established. Through example calculation, it’s confirmed that this method has a certain reliability and practicability.

Vertical Well-bore Section Anti-collision is one of the main problems to be resolved for clustering directional well during the construction process. In order to effectively reduce the Vertical Well Section collision risk of this wells, the relationship between Wellbore cross-collision probability and the Wellbore separation was studied, the relationship between Wellbore cross-collision probability and the parallel Section length of the two Wellbore was also studied, Based on the above study found the method to calculate the Vertical Wellbore Section cross-collision probability of the clustering directional well. The Vertical Well-bore Section arrangement with smallest cross-collision probability was found by analyzing the cross-collision probability in line style wellhead of cluster wells consisting of 4 wells through this method. The results show that when the Well-bore separation is less than 1.5m. Wellbore collision probability rapidly decrease with the increase of Well-bore separation, the wellbore collision probability trends to smooth when wellbore separation is more than this distance, and the tendency will increase with the increase of parallel section length of the two Wellbore. By optimizing the arrangement and design methods can effectively reduce the collision risk. This study provides a new idea to reduce the overall risk of Cluster Well development.

In order to solve the problem of concrete cracking in wellhead groove with large longitudinal length, shrinkage tests of concrete containing fly ash and slag in natural environment were conducted. According to the experimental study, the shrinkage model of concrete based on BP neural network is established and the results from model agree well with the measured results. Then the effect analysis of single factor on shrinkage using the neural network model is carried out. Simultaneously, the optimal mix proportion of concrete is successfully predicted by orthogonal experiment of numerical simulation method, so that it provides reference to the control of concrete shrinkage for the engineering structure.

The article introduces the advantages and the application of the visual design, analyzes the tendency and shortage of product development about high pressure valve used in wellhead. Combining the visual design method with collaborative design idea, a visual design system is designed for high pressure valve used in wellhead, which includes three modules. The development process and function of the system is described in detail. Based on a great deal database and modularized collaborative design, basic geometric design, three-dimensional modeling, virtual assembly and finite element analysis (FEA) on chief parts are finished successfully. Practice indicated that the visual design system was an effective measure to improve efficiency of design, meet the demand of the development of product serialization, and reduce the cycle of development of product, reduce the cost.

With the exploration of oil-gas field developing, more and more oil-gas well contain H2S, hydrogen sulfide stress corrosion has serious effect on production and restrict oil field development. With the applications of 1Cr13 steel in oil & gas wellhead, it is urgent to research hydrogen sulfide stress corrosion cracking (SSCC) properties in high-strength under the simulation condition of production. The tensile test under constant load and slow strain rate test (SSRT) were adopted to analyze the behaviors of 1Cr13 steel with orthogonal test under saturated H2S solution which included carbon dioxide under a partial pressure and its sample fracture was observed with SEM (Scanning Electron Microscope). Constant load tensile test is one of the first recognized by NACE to assess the performance of metallic materials against SSC approach under tensile stress in the aqueous solution which was in low pH value and H2S was saturated. Through the research above the mechanism of stress corrosion and the environmental factors that influence stress corrosion were investigated. The experimental results shown that the effects of environmental factors on SCC (Stress Corrosion Cracking) sensitivity of materials are in the following order: temperature effect > solution pH effect > chloride ion concentration effect, and 1Cr13 material has a better corrosion resistance for H2S and CO2 conditions under a certain stress so it can be proposed as the material of value for oil & gas wellhead. Through SEM it can be seen that the fracture is belonged to brittle fracture. The lattice bonding force is destroyed by hydrogen into the material that gathered in the certain crystal face and the material transform from plastic to brittleness, the material is failed, and SCC occurred.

Development of appropriate strategy for the management of reservoirs with sanding problems is rather complex and requires an integrated approach to finding the optimum solution to solving the problem. This requires integration of key aspects of reservoir characterisation, drilling, completion and production technologies including sand tolerances (Seabed wellhead/flow lines, topside facilities. Providing an accurate forecast of the tolerance depends on accurate prediction of sand failure and the corresponding volume of produced sand. This is a transient phenomena further complicated by gas reservoir fluid flow. In this paper the results of a comprehensive Thick Wall Cylinder[TWC] experimental sand production studies carried out on synthetic sandstones are presented. The sand production prediction model for liquid flow are further calibrated and upscaled with field data for gas reservoirs. The prediction model developed is further validated with independent field data with good results. The results represent a first for sand production forecast for gas reservoirs. Mitigation of sanding requires reliable sanding prediction, precise well design, accurate technology selection as well as optimum completion strategy.

Along with large scale application of cluster wells in Sulige gas field, the common low pressure flow meter can not be used in metering single well production with connecting wells in series. For this reason, we have developed a flow metering instrument of natural gas, which has the features of high static pressure, low differential pressure and high precision. Installed at the high pressure end of gas production wellhead, the instrument can bear 40Mpa static high pressure and has the features such as low pressure loss, broad measuring range, small temperature drift, high precision, long service life, solid, low cost and so on. With required measurement accuracy and resistance to pressure, which have been verified by the wide application, the instrument gave a solution to metering single well production of cluster wells.