scholarly journals A temperature-pressure coupling model for predicting gas temperature profile in gas drilling

2020 ◽  
pp. 193-193
Author(s):  
Jinjiang Liu ◽  
Wenlin Wu ◽  
Peng Qian ◽  
Shuo Wang

In the gas drilling design, accurate prediction of wellbore temperature profile is very crucial. Different from liquid drilling fluid, physical and thermo-physical parameters of gases are sensitive to the change of pressure and temperature, at the same time, the change of these parameters will react against the wellbore temperature and pressure. Based on the energy conservation principle, a temperature-pressure coupling calculation model was established to predict the gas temperature profile during gas drilling process. The model is solved by cycle coupling iteration method. The calculation shows that annular temperature rises sharply near the wellhead, drops sharply at bottom hole and is a little higher than the formation temperature in other places. Without considering the influence of friction heat, calculated temperature is lower than the actual temperature. Temperature trends are the same under different pump rates and larger pump rate leads to larger temperature range at the wellhead and at bottom hole. Compared with the pump rate, bit nozzle size has more influence on the temperature drop range. Temperature reduction increases from 31.3?C to 57.2?C while bit nozzle size decreases from 539 mm2 to 339 mm2.

2012 ◽  
Vol 524-527 ◽  
pp. 1423-1428
Author(s):  
Xun Cheng Song ◽  
Xiao Long Xu ◽  
Sha Sha Hu ◽  
Zhi Chuan Guan

Wellbore temperature is significant to well program and safety drilling for deep water drilling operations. On the basis of transient heat transfer mechanisms involved in deep water drilling among wellbore and formation and sea water, wellbore temperature profile, especially near sea bed and sensitivities to drilling fluid circulating duration, inlet temperature, water depth, water temperature, riser insulation and drilling fluid specific heat capacity have been analyzed via this model. Analysis show that deep-water wellbore temperature is much lower than a land well, the temperatures above sea bed normally ranges 10-30°C, and decreases with increased circulating duration; temperature at both outlet and bottom hole decreases drastically with increased water depth, and heat generation must be considered into estimating wellbore temperature profile especially one at bottom hole.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3533 ◽  
Author(s):  
Ruiyao Zhang ◽  
Jun Li ◽  
Gonghui Liu ◽  
Hongwei Yang ◽  
Hailong Jiang

The purpose of this paper is to discuss the variation of wellbore temperature and bottom-hole pressure with key factors in the case of coupled temperature and pressure under multi-pressure system during deep-water drilling circulation. According to the law of energy conservation and momentum equation, the coupled temperature and pressure calculation model under multi-pressure system is developed by using the comprehensive convective heat transfer coefficient. The model is discretized and solved by finite difference method and Gauss Seidel iteration respectively. Then the calculation results of this paper are compared and verified with previous research models and field measured data. The results show that when the multi-pressure system is located in the middle formation, the temperature of the annulus corresponding to location of the system is the most affected, and the temperature of the other areas in annulus is hardly affected. However, when the multi-pressure system is located at the bottom hole, the annulus temperature is greatly affected from bottom hole to mudline. In addition, the thermo-physical parameters of the drilling fluid can be changed by overflow and leakage. When only overflow occurs, the annulus temperature increases the most, but the viscosity decreases the most. When only leakage occurs, the annulus temperature decreases the most and the viscosity increases the most. However, when the overflow rate is greater than the leakage rate, the mud density and bottom-hole pressure increase the most, and both increase the least when only leakage occurs. Meanwhile, bottom-hole pressure increases with the increase of pump rate but decreases with the increase of inlet temperature. The research results can provide theoretical guidance for safe drilling in complex formations such as multi-pressure systems.


2017 ◽  
Vol 899 ◽  
pp. 469-473 ◽  
Author(s):  
Irineu Petri Jr. ◽  
Jéssika Marina dos Santos ◽  
Arley Silva Rossi ◽  
Marina Seixas Pereira ◽  
Claudio Roberto Duarte ◽  
...  

Drill cuttings generated by oil and gas drilling process are incorporated into the drilling fluid to ensure an efficient drilling and solids removal. The drilling rigs have a separation system accountable for separating drill cuttings and drilling fluids. Microwave drying is a new technology of separation that has been studied as an alternative to the currently drill cuttings dryer used. The results obtained in preliminary studies showed that this microwave drying is sensitive to different oxides presents into the rock. Thus, this study aimed to describe the microwave heating kinetics of some rocks in order to verify the interaction of oxides with electromagnetic waves. For this, the oxide contents of the rocks were determined by X-ray Fluorescence and different rocks were heated in a microwave heating unit. The results showed that the relationship between the temperature and heating time is exponential and depends on the rock oxide contents. It was found that the iron oxides may be unstable at microwave and rocks with high levels of magnesium oxides and sulfates tend to be good absorbers of microwave. Rocks containing high levels of calcium, silicon, titanium, barium and chloride (NaCl) are not good absorbers of microwave. It was also noted that faster solid heating, lesser the efficiency of microwave drying.


SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1201-1212 ◽  
Author(s):  
Ben Li ◽  
Hui Li ◽  
Boyun Guo ◽  
Xiao Cai ◽  
Mas lwan Konggidinata

Summary Gas-hydrate cuttings are conveyed upward by the drilling fluid through the outer drillpipe/wellbore annulus during the gas-hydrate-well-drilling process. The temperature profile along the wellbore during the drilling process has not been thoroughly investigated because the gas-hydrate cuttings could affect the temperature of the drilling fluid along the wellbore. As the mixture of drilling fluid and gas hydrates flows from the bottom to the surface, the methane and other hydrocarbons present in the gas hydrates would change from liquid to gas phase and further cause well-control issues. Furthermore, the bottomhole pressure would decrease and could not provide sufficient balance to the formation pressure, which could significantly increase the risk of well blowout. A numerical solution is presented in this paper to predict the temperature profile of the gas-hydrate well during the drilling process. The main considerations were the following: Hydrate cuttings entrained in the bottom of the hole would affect the temperature of the fluid in the annulus space. The entrained hydrate cuttings could affect the fluid thermal properties in the drillstring and in the annulus. Because of the Joule-Thomson cooling effect at the outlet of the nozzles, the fluid temperature at the bottom of the hole was lower than that above the drill-bit nozzles. Hence, the gas-hydrate-dissociation characteristics were considered and integrated in the proposed numerical model. The numerical model was validated by comparing the obtained data with the Shan et al. (2016) analytical model. In addition, the obtained data were also compared with the measured temperature data of a conventional well drilled in China and a gas-hydrate-well drilling record in India. Sensitivity analysis was used to evaluate the effects of the pumping rate, Joule-Thomson effect, and injection drilling-mud temperature on the annulus temperature-profile distribution. It was found that the injection drilling-mud temperature and pumping rate could affect the temperature profile in the annulus, whereas the Joule-Thomson effect could decrease the annulus temperature of the drilling mud near the bottom.


2021 ◽  
Vol 62 (3a) ◽  
pp. 76-84
Author(s):  
Tuan Tran Nguyen ◽  
Son Hoang Nguyen ◽  

This paper presents some studies on the application of mud cooler in Oil and Gas drilling in a high temperature, high pressure condition of Cuu Long reservoir. The authors have proposed a method to study the theory of temperature effects on drilling fluid properties, that have been tested practically. The authors have remarked on each type of drilling rig and installation location. With these remarks, the authors give an option to install the "Mud cooler" on the rig at the appropriate location and method so that the temperature of the solution will be ensured to reduce to a safe level. The effective application of this equipment has greatly assisted drilling process since the fluid temperature has been reduced sharply before returning to the mud tank. This has helped cut down expenses significantly by prolonging eqipment's endurability, saving time for drilling, ship renting, drilling services and minimize the budget spent on buying the fluid and additives to recover it. Thus, the drilling workers' working conditions have been facilitated. The results of these studies have been proved scientifically and practically through the successful drilling of well ST-3P-ST. This will make the way for other local wells and reservoirs which have the same conditions of temperature and pressure.


2015 ◽  
Vol 8 (1) ◽  
pp. 451-456 ◽  
Author(s):  
Fanhe Meng ◽  
Aiguo Yao ◽  
Shuwei Dong

In order to carry out a series of key basic researches, a scientific ultra-deep drilling plan is being undertaken in China. Wellbore temperature is one of the key factors during the drilling process. In this paper, we established a twodimensional transient numerical model to predict the ultra-deep wellbore temperature distributions during circulation and shut-in stages. The simulation results indicate that the cooling effect of drilling fluid circulation is very obvious, especially during the inception phase. Drilling fluid viscosity has great influence on the temperature distributions during circulation stage: the lower the viscosity, the higher the bottomhole temperature. While drilling fluid displacement and inlet temperature have a little effect on the bottomhole temperature. During the shut-in stage, the wellbore temperature recovery is a slow process.


2021 ◽  
Author(s):  
Wenzhe Li ◽  
Liang Tang ◽  
Ye Zhuang ◽  
Lu Zhang ◽  
Yifan Cai ◽  
...  

Abstract The Sichuan shale gas deposits are in remote, mountainous regions and the gas-bearing rocks are deep and in tectonically complicated areas. The plan to make shale gas account for more than 40% of the Chinese total natural gas production by 2040 requires shorter well delivery periods and higher well productions. It is therefore crucial to improve the overall drilling efficiency with the limited rig capability and geological challenges. To improve capital efficiency, a multi-disciplinary approach integrating subsurface understanding with well engineering and drilling practices was implemented. Central to this drilling optimization effort are risk mitigation strategies, utilizing solutions based on robust geomechanical understanding and critical drilling experience reviews, engineered to improve wellbore placement, drilling fluid formulation, and bit and BHA designs. A novel wellbore-strengthening oil-based mud system was implemented to maintain shale stability. A rotary steerable drilling system and reservoir navigation technology were deployed together with the application of specific poly-crystalline diamond compact (PDC) bit design. A new-generation advanced cuttings analysis method was also applied with the lithology, organic matter and fracability of rock could be evaluated in real time to assist the reservoir navigation during the drilling. This integrated solution was deployed in the drilling of 8 ½" holes of Changning Shale gas field. A cross-functional team was formed so that the operator, the drilling contractor and the service company can collaborate closely with expertise across multiple functions and disciplines. Suitable mud weight was provided by the detailed geomechanical analysis to account for the high pore pressure and near bed-parallel drilling conditions. To place the laterals in the thin targeted sub-layer with high TOC, a rotary steerable system (RSS) with azimuthal GR provide not only precise steering and directional controls, but also enable increased reservoir coverage by expanding the lateral section as well as drilling the build and horizontal sections in a single run without BHA trips. The combination of RSS with specialized bits as an optimized bit and BHA system maximizes the steering performance while delivering superior borehole quality by reducing drill string vibration and the minimizing mechanical specific energy, all of which contribute to the overall improvement in the well delivery efficiency. This integrated drilling solution has achieved remarkable results by doubling the average rate of penetration (ROP) to 15.5m/h compared to an offset well on the same pad of 7.4m/h. The well was placed successfully in the targeted zone with a 100% reservoir contact. And the total drilling time was shortened by 40% compared to similar wells nearby. The integrated solution has brought breakthrough to improve the well delivery efficiency in the China shale gas development. This paper describes the integrated workflow solutions and detailed technical optimizations of the 8 ½" section drilling process.


Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.


2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Qilong Xue ◽  
Ruihe Wang ◽  
Baolin Liu ◽  
Leilei Huang

In the oil and gas drilling engineering, measurement-while-drilling (MWD) system is usually used to provide real-time monitoring of the position and orientation of the bottom hole. Particularly in the rotary steerable drilling technology and application, it is a challenge to measure the spatial attitude of the bottom drillstring accurately in real time while the drillstring is rotating. A set of “strap-down” measurement system was developed in this paper. The triaxial accelerometer and triaxial fluxgate were installed near the bit, and real-time inclination and azimuth can be measured while the drillstring is rotating. Furthermore, the mathematical model of the continuous measurement was established during drilling. The real-time signals of the accelerometer and the fluxgate sensors are processed and analyzed in a time window, and the movement patterns of the drilling bit will be observed, such as stationary, uniform rotation, and stick–slip. Different signal processing methods will be used for different movement patterns. Additionally, a scientific approach was put forward to improve the solver accuracy benefit from the use of stick–slip vibration phenomenon. We also developed the Kalman filter (KF) to improve the solver accuracy. The actual measurement data through drilling process verify that the algorithm proposed in this paper is reliable and effective and the dynamic measurement errors of inclination and azimuth are effectively reduced.


2020 ◽  
pp. 70-74
Author(s):  
V.V. Guliyev ◽  
◽  
◽  

Currently, a great number of drilling fluids with different additives are used all over the world. Such additives are applied to control the properties of the drilling mud. The main purpose for controlling is to achieve more effective and safe drilling process. This research work aims to develop Water-Based Mud (WBM) with a Coefficient of Friction (CoF) as low as Oil-Based Mud (OBM) and better rheological properties. As it is known, produced CoF by WBM is higher than OBM, which means high friction between wellbore or casing and drill string. It was the reason for studying the effect of nanosilica on drilling fluid properties such as lubricity, rheological parameters and filtrate loss volume of drilling mud. The procedures were carried out following API RP 13B and API 13I standards. Five concentrations of nanosilica were selected to be tested. According to the results obtained, it was defined that adding nanosilica into the mud decreases CoF of basic WBM by 26 % and justifies nanosilica as a good lubricating agent for drilling fluid. The decreasing trend in coefficient of friction and plastic viscosity for nanosilica was obtained until the concentration of 0.1 %. This reduction is due to the shear thinning or pseudoplastic fluid behavior. After 0.1 %, an increase at PV value trend indicates that it does not follow shear thinning behavior and after reaching a certain amount of dissolved solids in the mud, it acts like normal drilling fluid. The yield point of the mud containing nanoparticles was higher than the basic one. Moreover, a growth in the concentration leads to an increase in yield point value. The improvement of this fluid system cleaning capacity via hydraulics modification and wellhole stability by filter cake endurance increase by adding nanosilica is shown as well. The average well construction data of “Neft Dashlary” field was used for the simulation studies conducted for the investigation of hydraulics parameters of reviewed fluids for all series of experiments. The test results were accepted reliable in case of at least 3 times repeatability.


Sign in / Sign up

Export Citation Format

Share Document