scholarly journals Estimation of Wellbore and Formation Temperatures during the Drilling Process under Lost Circulation Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Mou Yang ◽  
Yingfeng Meng ◽  
Gao Li ◽  
Yongjie Li ◽  
Ying Chen ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Oil And Gas ◽  
Exchange Process ◽  
Drilling Process ◽  
Formation Temperature ◽  
Well Drilling ◽  
Lost Circulation ◽  
Deep Well ◽  
Completion Process ◽  
Oil And Gas Resources

Significant change of wellbore and surrounding formation temperatures during the whole drilling process for oil and gas resources often leads by annulus fluid fluxes into formation and may pose a threat to operational security of drilling and completion process. Based on energy exchange mechanisms of wellbore and formation systems during circulation and shut-in stages under lost circulation conditions, a set of partial differential equations were developed to account for the transient heat exchange process between wellbore and formation. A finite difference method was used to solve the transient heat transfer models, which enables the wellbore and formation temperature profiles to be accurately predicted. Moreover, heat exchange generated by heat convection due to circulation losses to the rock surrounding a well was also considered in the mathematical model. The results indicated that the lost circulation zone and the casing programme had significant effects on the temperature distributions of wellbore and formation. The disturbance distance of formation temperature was influenced by circulation and shut-in stages. A comparative perfection theoretical basis for temperature distribution of wellbore-formation system in a deep well drilling was developed in presence of lost circulation.

The Feasibility for Potassium-Based Phosphate Brines To Serve as High-Density Solid-Free Well-Completion Fluids in High-Temperature/High-Pressure Formations

SPE Journal ◽  
2018 ◽  
Vol 24 (05) ◽  
pp. 2033-2046 ◽  
Author(s):  
Hu Jia ◽  
Yao–Xi Hu ◽  
Shan–Jie Zhao ◽  
Jin–Zhou Zhao
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil And Gas ◽  
Pressure Coefficient ◽  
High Density ◽  
Well Drilling ◽  
Well Completion ◽  
Oil And Gas Resources ◽  
Completion Fluids ◽  
High Temperature High Pressure

Summary Many oil and gas resources in deep–sea environments worldwide are often located in high–temperature/high–pressure (HT/HP) and low–permeability reservoirs. The reservoir–pressure coefficient usually exceeds 1.6, with formation temperature greater than 180°C. Challenges are faced for well drilling and completion in these HT/HP reservoirs. A solid–free well–completion fluid with safety density greater than 1.8 g/cm3 and excellent thermal endurance is strongly needed in the industry. Because of high cost and/or corrosion and toxicity problems, the application of available solid–free well–completion fluids such as cesium formate brines, bromine brines, and zinc brines is limited in some cases. In this paper, novel potassium–based phosphate well–completion fluids were developed. Results show that the fluid can reach the maximum density of 1.815 g/cm3 at room temperature, which makes a breakthrough on the density limit of normal potassium–based phosphate brine. The corrosion rate of N80 steel after the interaction with the target phosphate brine at a high temperature of 180°C is approximately 0.1853 mm/a, and the regained–permeability recovery of the treated sand core can reach up to 86.51%. Scanning–electron–microscope (SEM) pictures also support the corrosion–evaluation results. The phosphate brine shows favorable compatibility with the formation water. The biological toxicity–determination result reveals that it is only slightly toxic and is environmentally acceptable. In addition, phosphate brine is highly effective in inhibiting the performance of clay minerals. The cost of phosphate brine is approximately 44 to 66% less than that of conventional cesium formate, bromine brine, and zinc brine. This study suggests that the phosphate brine can serve as an alternative high–density solid–free well–completion fluid during well drilling and completion in HT/HP reservoirs.

scholarly journals Research Risk Factors in Monitoring Well Drilling—A Case Study Using Machine Learning Methods

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1293
Author(s):  
Shamil Islamov ◽  
Alexey Grigoriev ◽  
Ilia Beloglazov ◽  
Sergey Savchenkov ◽  
Ove Tobias Gudmestad
Keyword(s):  
Machine Learning ◽  
Anomaly Detection ◽  
Oil And Gas ◽  
New Technologies ◽  
Learning Algorithms ◽  
Gas Production ◽  
Machine Learning Algorithms ◽  
Gradient Boosting ◽  
Drilling Process ◽  
Well Drilling

This article takes an approach to creating a machine learning model for the oil and gas industry. This task is dedicated to the most up-to-date issues of machine learning and artificial intelligence. One of the goals of this research was to build a model to predict the possible risks arising in the process of drilling wells. Drilling of wells for oil and gas production is a highly complex and expensive part of reservoir development. Thus, together with injury prevention, there is a goal to save cost expenditures on downtime and repair of drilling equipment. Nowadays, companies have begun to look for ways to improve the efficiency of drilling and minimize non-production time with the help of new technologies. To support decisions in a narrow time frame, it is valuable to have an early warning system. Such a decision support system will help an engineer to intervene in the drilling process and prevent high expenses of unproductive time and equipment repair due to a problem. This work describes a comparison of machine learning algorithms for anomaly detection during well drilling. In particular, machine learning algorithms will make it possible to make decisions when determining the geometry of the grid of wells—the nature of the relative position of production and injection wells at the production facility. Development systems are most often subdivided into the following: placement of wells along a symmetric grid, and placement of wells along a non-symmetric grid (mainly in rows). The tested models classify drilling problems based on historical data from previously drilled wells. To validate anomaly detection algorithms, we used historical logs of drilling problems for 67 wells at a large brownfield in Siberia, Russia. Wells with problems were selected and analyzed. It should be noted that out of the 67 wells, 20 wells were drilled without expenses for unproductive time. The experiential results illustrate that a model based on gradient boosting can classify the complications in the drilling process better than other models.

scholarly journals Risk Factors Evaluation for Monitoring of Well Drilling

2021 ◽  
Author(s):  
Shamil Islamov ◽  
Alexey Grigoriev ◽  
Ilya Beloglazov ◽  
Sergey Savchenkov ◽  
Ove Tobias Gudmestad
Keyword(s):  
Anomaly Detection ◽  
Oil And Gas ◽  
New Technologies ◽  
Warning System ◽  
Time Frame ◽  
Gas Production ◽  
Machine Learning Algorithms ◽  
Gradient Boosting ◽  
Drilling Process ◽  
Well Drilling

Drilling of wells for oil and gas production is a highly complex and expensive part of reservoir development. Thus, together with injury prevention, there is a goal to save cost expenditures on downtime and repair of drilling equipment. Nowadays companies have begun to look for ways to improve the efficiency of drilling and minimize non-production time with the help of new technologies. To support decisions in a narrow time frame, it is valuable to have an early warning system. Such a decision support system will help an engineer to intervene in the drilling process and prevent high expenses of unproductive time and equipment repair due to a problem. This work is describing a comparison of machine learning algorithms for anomaly detection during well drilling. Tested models classify drilling problems based on historical data from previously drilled wells. To validate anomaly detection algorithms, we use historical logs of drilling problems for 67 wells at a large brownfield in Siberia, Russia. Wells with problems were selected and analyzed. It should be noted that out of the 67 wells, 20 wells were drilled without expenses for unproductive time. Experiential results illustrated that a model based on gradient boosting can classify the complications in the drilling process best of all.

Application of Ultrafine Weighting Materials in High-Density Oil-Based Drilling Fluid Technology

2015 ◽  
Vol 814 ◽  
pp. 338-344 ◽  
Author(s):  
Yan Ye ◽  
Wen Hua An ◽  
Da Yin ◽  
Qing Wen Zhang ◽  
Lei Li ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Fine Powder ◽  
High Density ◽  
Suspension Stability ◽  
Drilling Fluids ◽  
Powder Particle Size ◽  
Drilling Process ◽  
Well Drilling ◽  
Base Oil ◽  
Lost Circulation

High-density oil-based drilling fluid already was considered as one of the most effective technologies during the HTHP Ultra-deep well drilling process. The weighting materials sag such as barite sag, however, always occurred because of the density contrast between the base oil and the weighting material, and hence sag can result in excessive torque, lost circulation and many other problems. This study applied three kinds of ultra-fine powder (particle size≤4μm), which are new weighting materials, to replace the common API barite (particle size10~70μm). The different kinds of high-density oil-based drilling fluids, which weighted with micronized barite, micronized ilmenite, manganese tetraoxide and API barite, were prepared and evaluated separately in lab. The performance data showed that compared with conventional weighting materials, the application of ultrafine powder technology could greatly optimize the rheology of high-density oil-based drilling fluids (ρ ≥ 2.3 g/cm3), reduce the amount of emulsifiers about 50% and dramatically enhance the dynamic suspension-stability of the system, Furthermore, OBM drilling fluids weighted with ultrafine weighting materials almost presented lower viscosity, shear force and sedimentation rate, which will meet more severe requirements of ultra-deep complex well drilling.

scholarly journals НАУКОВІ ТЕНДЕНЦІЇ БУРІННЯ ГЛИБОКИХ НАФТОГАЗОВИХ СВЕРДЛОВИН

2019 ◽  
Vol 1 (1(31)) ◽  
pp. 18-21
Author(s):  
Мирослава Чернова
Keyword(s):  
High Pressure ◽  
Corrosion Fatigue ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Well Drilling ◽  
Gas Industry ◽  
Deep Well ◽  
Deep Wells ◽  
Deformed State ◽  
Drill Column

The essential problems in oil and gas industry are corrosion-fatigue breakage of drill column elements, sticking of drilling and heavy-weight drill pipes, taking place in drilling of directional and horizontal wells. The stickings are caused by friction, emerging between sides of hole and elements of drilling column. The frictions block assurance of core integrity in core receive. The failure resistance by using polymer and composite materials for surface treatment under influence of triboprocess and corrosion-fatigue breakage is considered in the article.The problem of deep well drilling is considered, which is connected with the prevention of the seizure phenomenon between the walls of the drill column and the barrel of deep wells. The design of the coupling connection of casing pipes with a high pressure sealing element is provided to provide the tightness of the casing columns at high pressure and temperature parameters. The elastically deformed state of the pipes with the inserted sealing element is scientifically substantiated.

scholarly journals Geological conditions of generation and distribution of abnormal high formation pressure in Ninotsminda and Manavi fields sedimentary cover (near Tbilisi oil and gas region)

2020 ◽  
pp. 75-104
Author(s):  
Mevlud Sharikadze ◽  
◽  
Irakli Tavdumadze ◽  
Zurab Suramelashvili ◽  
◽  
...  
Keyword(s):  
Oil And Gas ◽  
Sedimentary Cover ◽  
Wide Distribution ◽  
Formation Pressure ◽  
Well Drilling ◽  
Deep Well ◽  
North East ◽  
Abnormal Pressure ◽  
Geological Conditions ◽  
Pressure Maximum

Abnormal high formation pressure (AHFP) zones are widely spread in sedimentary cover of numerous oil and gas regions of the world and our fields are among them. A lot of money and time are spent on elimination of some drilling complications of relevant intervals and that makes well costs more expensive. Therefore, study of forecast abnormal pressure generation and distribution zones is one of the current problems of deep well drilling activities. According to the drilling, geological and geophysical data analyzes and references, the generation of abnormal pressure in the sedimentary cover of the studied territory is mainly caused by: the existence of long submerged sedimentary basin, wide distribution of thick plastic clayey formations enriched with bentonite, primate of submersion velocity against persistence of hardening of faeces, intense folding of formations and frequent network of fault dislocations. Stratigraphically AHFP zone corresponds mainly with Middle Sarmatian-Maikopian-Upper Eocene clayey-sandstone suit distribution intervals. Formation pressure maximum gradient within the region varies from 1.75-1.85 to 2.00-2.20, intervals of distribution AHFP zones - from 600-2200m to 3700-4500m, thicknesses - from 700-2100m to 2500-3000m. Indicators of the given parameters generally increase roughly from South-West to North-East towards the thicknesses of plastic clayey formations, their submersion depth and tectonic tense growth factor. Besides, geological characteristics of some particular areas cause some adjustments: AHFP zone is hypsometrically aroused in the hinge lines of fault anticlines and is sunk in syncline depressions, thickness and formation pressure gradients are less in anticlines than in synclines.

scholarly journals Study of Downhole Shock Loads for Ultra-Deep Well Perforation and Optimization Measures

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2743 ◽  
Author(s):  
Qiao Deng ◽  
Hui Zhang ◽  
Jun Li ◽  
Xuejun Hou ◽  
Hao Wang
Keyword(s):  
Oil And Gas ◽  
Technical Problem ◽  
Calculation Model ◽  
Shock Loads ◽  
Multiple Factors ◽  
Deep Well ◽  
Oil And Gas Resources ◽  
Unconventional Oil And Gas ◽  
Important Direction ◽  
Dynamics Models

Ultra-deep well perforation is an important direction for the development of unconventional oil and gas resources, the security with shock loads is a difficult technical problem. Firstly, the theoretical analysis of perforated string is carried out, the dynamics models of which are established in the directions of axial, radial and circumferential. Secondly, the process of perforating with hundreds of bullets is simulated by using the software of LS-DYNA (ANSYS, Inc, Pennsylvania, USA). The propagation attenuation model of shock loads is established, and a calculation model to predict shock loads at different positions of the tubing interval has been fitted by considering multiple factors. The dynamic response of perforated string is studied, and the vulnerable parts of which are found out. Thirdly, the optimization measures are put forward for ultra-deep well perforation by the design of shock adsorption and safety distance of the packer. Finally, the field case of an ultra-deep well shows that the research method in this paper is practical, and the optimization measures are reasonable and effective. This study can provide important guidance to reduce shock damage and improve security for ultra-deep well perforation.

Harmonic Response Analysis and Structure Modification for Substructure of Deep Well Drilling Rig

2016 ◽  
Vol 826 ◽  
pp. 45-49
Author(s):  
Jian Hua ◽  
Hong Wu Zhu ◽  
Si Zhu Zhou ◽  
Lei Hu ◽  
Hao Cui
Keyword(s):  
Response Characteristic ◽  
Response Analysis ◽  
Drilling Process ◽  
Rotary Table ◽  
Eccentric Rotation ◽  
Well Drilling ◽  
Harmonic Response ◽  
Drilling Rig ◽  
Deep Well ◽  
Harmonic Response Analysis

During the oil drilling process, the eccentric rotation of rotating devices such as rotary table may excite abnormal vibration of the drilling rig which will worsen the working condition of the rig and cause structure failure. In this paper, a ZJ70 drilling rig is taken as the study object, the harmonic response analysis of which is conducted by using FEM software and the frequency response characteristic of the substructure is obtained. Result shows the stiffness of rear substructure is insufficient. On the basis of harmonic response analysis, the modification of the substructure is carried out through enlarging the rear connection frame. Further calculation shows the first 3 order natural frequencies of the substructure are increased, thus the abnormal vibration of the substructure caused by the rotary table with certain rotation speed can be effectively reduced. In addition, the displacement response of both first two orders are greatly decreased with that of central and rear positions are respectively decreased by 17.5% and 42.1%, which demonstrates the dynamic characteristic of the substructure is significantly improved.

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