scholarly journals Wellbore Temperature and Pressure Field in Deep-water Drilling and the Applications in Prediction of Hydrate Formation Region

2021 ◽  
Vol 9 ◽  
Author(s):  
Wantong Sun ◽  
Na Wei ◽  
Jinzhou Zhao ◽  
Shouwei Zhou ◽  
Liehui Zhang ◽  
...  
Keyword(s):  
Deep Water ◽  
Drilling Fluid ◽  
Hydrate Formation ◽  
Prediction Method ◽  
Geothermal Gradient ◽  
Formation Region ◽  
Fully Implicit ◽  
Wellbore Pressure ◽  
Wellbore Temperature ◽  
Influence Degree

In the process of deep-water drilling, gas hydrate is easily formed in wellbores due to the low temperature and high pressure environment. In this study, a new, systematic, and accurate prediction method of temperature, pressure, and hydrate formation region in wellbores is developed. The mathematical models of wellbore pressure and transient heat transfer are established, the numerical solution method based on fully implicit finite difference method is developed, and the accuracy is verified by comparing with the field measured data. Combined with the hydrate phase equilibrium model, the hydrate formation region in wellbore is predicted, and the sensitivity effects of nine factors on wellbore temperature, pressure, and hydrate formation region are analyzed. Finally, the influence regularities and degree of each parameter are obtained. The increases of circulation time, geothermal gradient, displacement of drilling fluid, and injection temperature will inhibit the formation of hydrate in wellbores, and the influence degree increases in turn; the increases of wellhead backpressure and seawater depth will promote the formation of hydrate in wellbores, and the influence degree increases in turn. The changes of drilling fluid density, well depth, and hole deviation angle have little effect on the formation of hydrate in wellbores.

Full Transient Features of Heat Transfer and Sensitivities on Deep Water Wells

2012 ◽  
Vol 524-527 ◽  
pp. 1423-1428
Author(s):  
Xun Cheng Song ◽  
Xiao Long Xu ◽  
Sha Sha Hu ◽  
Zhi Chuan Guan
Keyword(s):  
Heat Transfer ◽  
Temperature Profile ◽  
Water Depth ◽  
Deep Water ◽  
Sea Water ◽  
Drilling Fluid ◽  
Inlet Temperature ◽  
Bottom Hole ◽  
Sea Bed ◽  
Wellbore Temperature

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.

Analysis of Wellbore Temperature Distribution and Influencing Factors During Drilling Horizontal Wells

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Zheng Zhang ◽  
Youming Xiong ◽  
Fang Guo
Keyword(s):  
Temperature Distribution ◽  
Significant Influence ◽  
Drilling Fluid ◽  
Geothermal Gradient ◽  
Transient Temperature ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Horizontal Section ◽  
Geothermal Resources ◽  
Wellbore Temperature

Horizontal well drilling technology is widely used in the exploitation of petroleum and natural gas, shale gas, and geothermal resources. The temperature distribution of wellbore and surrounding formation has a significant influence on safe and fast drilling. This study aims to investigate the temperature distribution of horizontal wellbores during circulation by using transient temperature model. The transient temperature prediction model was established by the energy conservation law and solved by the relaxation iterative method. The validity of the model has been verified by the field data from the Tarim Oilfield. The calculation results showed that the highest temperature of the drilling fluid inside the drill string was at the bottomhole and the highest temperature of annulus drilling fluid was at some depth away from the bottomhole. Sensitivity analysis of various factors that affect the temperature distribution of annulus drilling fluid were carried out, including the circulation time, the flow rate, the density of drilling fluid, the inlet temperature, the vertical depth, the horizontal section length, and the geothermal gradient. It can be found that the vertical depth and the geothermal gradient have a significant influence on the bottomhole temperature, and inlet temperature plays a decisive influence on the outlet temperature. These findings can supply theoretical bases for the horizontal wellbore temperature distribution during drilling.

scholarly journals Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

2017 ◽  
Author(s):  
Xiuhua Zheng ◽  
Chenyang Duan ◽  
Zheng Yan ◽  
Hongyu Ye ◽  
Zhiqing Wang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Drilling Fluid ◽  
Model Fitting ◽  
Geothermal Gradient ◽  
Pressure Control ◽  
Geothermal Field ◽  
Drilling Fluids ◽  
Geothermal Well ◽  
Time Flow ◽  
Wellbore Pressure

The accurate wellbore pressure control not only prevents from lost circulation/blowout and fracturing formation by managing density of drilling fluid, but also improves productivity by mitigating reservoir damage. The geothermal pressure calculated by constant parameters for geothermal well would bring big error easily, as the changes of physical, rheological and thermal properties of drilling fluids with temperature were neglected. This paper researches the wellbore pressure coupling by calculating the temperature distribution with existed model, fitting the rule of density of drilling fluid with temperature and establishing mathematical models to stimulate the wellbore pressures, which is expressed as the variation of Equivalent Circulating Density (ECD) under different conditions. With this method, temperature and ECDs in the wellbore of the first medium-deep geothermal well ZK212 Yangyi Geothermal Field in Tibet were determined, and the sensitivity analysis was simulated by assumed parameters, i.e. circulating time, flow rate, geothermal gradient, diameters of wellbore, rheological models and regimes, the results indicated the geothermal gradient and flow rate were the most influence parameters on the temperature and ECD distribution, and additives added in drilling fluid should be careful which would change the properties of drilling fluid and induce the temperature redistribution. To make sure the safe drilling, velocity of pipes tripping into the hole, depth and diameter of wellbore are considered to control the surge pressure.

scholarly journals Hydrate Formation and Decomposition Regularities in Offshore Gas Reservoir Production Pipelines

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 248 ◽  
Author(s):  
Na Wei ◽  
Wantong Sun ◽  
Yingfeng Meng ◽  
Jinzhou Zhao ◽  
Bjørn Kvamme ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Numerical Solutions ◽  
Sea Water ◽  
Hydrate Formation ◽  
Gas Production ◽  
Gas Reservoir ◽  
Solution Algorithms ◽  
Wellbore Pressure ◽  
Wellbore Temperature ◽  
Temperature And Pressure

In recent years, the exploitation and utilization of offshore oil and gas resources have attracted more attention. In offshore gas reservoir production, wellbore temperature and pressure change continuously when water-bearing natural gas flows upward. The wellbore temperature is also affected by the low-temperature sea water. The combination of temperatures and pressures controlled by the upward flow, and cooling from the surrounding seawater frequently leads to the conditions of temperature and pressure for hydrate formation. This can lead to pipeline blockage and other safety accidents. In this study, we utilize mathematical models of hydrate phase equilibrium, wellbore temperature, wellbore pressure to study hydrate formation and decomposition in offshore gas reservoir production. Numerical solution algorithms are developed and numerical solutions are validated. The sensitivity influence of different parameters on the regions and regularities of hydrate formation and decomposition in wellbores are obtained through numerical simulations. It is found that increased daily gas production, water content, or geothermal gradient in offshore gas reservoir production pipelines results in less hydrate formation in the wellbores. Accordingly, the risk of wellbore blockage decreases and production safety is maintained. Decreased tubing head pressure or seawater depth results in similar effects. The result of this study establishes a set of prediction methods for hydrate formation and decomposition that can be used in the development of guidelines for safe construction design.

Study of dynamic pressure on the packer for deep-water perforation

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 215-223
Author(s):  
Hao Huang ◽  
Qiao Deng ◽  
Hui Zhang
Keyword(s):  
Deep Water ◽  
Peak Pressure ◽  
Orthogonal Design ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Calculation Model ◽  
Well Testing ◽  
Technical Problems ◽  
Wellbore Pressure ◽  
Three Dimensional Finite Element

Abstract The packer is one of the most important tools in deep-water perforation combined well testing, and its safety directly determines the success of perforation test operations. The study of dynamic perforating pressure on the packer is one of the key technical problems in the production of deep-water wells. However, there are few studies on the safety of packers with shock loads. In this article, the three-dimensional finite element models of downhole perforation have been established, and a series of numerical simulations are carried out by using orthogonal design. The relationship between the perforating peak pressure on the packer with the factors such as perforating charge quantity, wellbore pressure, perforating explosion volume, formation pressure, and elastic modulus is established. Meanwhile, the database is established based on the results of numerical simulation, and the calculation model of peak pressure on the packer during perforating is obtained by considering the reflection and transmission of shock waves on the packer. The results of this study have been applied in the field case of deep-water well, and the safety optimization program for deep-water downhole perforation safety has been put forward. This study provides important theoretical guidance for the safety of the packer during deep-water perforating.

Investigation on Methane Hydrate Formation in Water-based Drilling Fluid

2021 ◽  
Vol 35 (6) ◽  
pp. 5264-5270
Author(s):  
Yong He ◽  
Zhen Long ◽  
Jingsheng Lu ◽  
Lingli Shi ◽  
Wen Yan ◽  
...  
Keyword(s):  
Methane Hydrate ◽  
Drilling Fluid ◽  
Hydrate Formation ◽  
Water Based

Potassium carbonate based deep eutectic solvent (DES) as a potential drilling fluid additive in deep water drilling applications

2021 ◽  
pp. 1-20
Author(s):  
Muhammad Hammad Rasool ◽  
Asif Zamir ◽  
Khaled A. Elraies ◽  
Maqsood Ahmad ◽  
Muhammad Ayoub ◽  
...  
Keyword(s):  
Deep Water ◽  
Potassium Carbonate ◽  
Drilling Fluid ◽  
Deep Eutectic Solvent

Numerical Integration of the AUSMV Scheme With a Dynamic Wellbore Temperature Model

2018 ◽  
Author(s):  
John Emeka Udegbunam ◽  
Kjell Kåre Fjelde ◽  
Dan Sui
Keyword(s):  
Dynamic Models ◽  
Drilling Fluid ◽  
Splitting Method ◽  
Isothermal Condition ◽  
Temperature Model ◽  
Two Phase ◽  
Transient Model ◽  
Flux Vector Splitting ◽  
Wellbore Temperature ◽  
Transient Models

The AUSMV scheme is a hybrid transient model derived from Advection-Upwind-Splitting Method (AUSM) and Flux Vector Splitting (FVS) method. The two-phase flow model was formulated under isothermal condition. This neglected the behavior of temperature during transient scenarios, for instance, unloading and drilling fluid circulation. In contrast to this assumption, wellbore temperature changes locally with time under such dynamic conditions. The numerical accuracy of the AUSMV scheme can be improved in two ways. The scheme can be reformulated by including energy equation in the system of governing conservation laws. This option, however, is computationally rigorous and expensive. A better alternative is to develop a separate dynamic temperature model that will calculate wellbore and formation temperatures. Then the two dynamic models — the AUSMV scheme and temperature model — are numerically coupled into a thermohydraulic simulator. The present work will include a brief introduction to the AUSMV scheme, followed by the description of the temperature model. In addition, how the two transient models are integrated will be presented. Simulation cases, demonstrating the improved modeling capability of the scheme for a drilling situation, will be shown.

scholarly journals Study on Method of Determining the Safe Operation Window of Drilling Fluid Density with Credibility in Deep Igneous Rock Strata

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chao Han ◽  
Zhichuan Guan ◽  
Chuanbin Xu ◽  
Fuhui Lai ◽  
Pengfei Li
Keyword(s):  
Igneous Rock ◽  
Drilling Fluid ◽  
Prediction Method ◽  
Large Error ◽  
Fluid Density ◽  
Safe Operation ◽  
Collapse Pressure ◽  
Modified Method ◽  
Fracture Pressure ◽  
Rock Strata

It is difficult to determine the safe operation window of drilling fluid density (SOWDFD) for deep igneous rock strata. Although the formation three-pressure (pore pressure, collapse pressure, and fracture pressure) prediction method with credibility improves the accuracy of formation three-pressure prediction, it still has a large error for deep igneous strata. To solve this problem, a modified method of the SOWDFD in deep igneous rock strata is proposed based on the leakage statistics of adjacent wells. This method is based on the establishment of the SOWDFD with credibility. Through statistical analysis of drilling fluid density of igneous rock leaky formation group in adjacent wells, the fracture leakage law of the formation is revealed and the upper limit of leak-off pressure containing probability information is obtained. Finally, the modified SOWDFD with credibility for deep igneous rock strata is formed. In this work, the proposed method was used to compute the SOWDFD with credibility of SHB well in Xinjiang, China. Results show that the modified density window is consistent with the field drilling conditions and can reflect the narrow density window in the Permian and lower igneous strata. Combined with the formation three-pressure prediction method with credibility and the actual leakage law of adjacent wells, it can effectively improve the prediction accuracy of the SOWDFD for deep igneous rock strata. The findings of the study can help in better understanding of the complex downhole geological environment in deep igneous rock strata and making reasonable drilling design scheme.

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