scholarly journals Drilling in Karstified Carbonates: Early Risk Detection Technique

2020 ◽  
Author(s):  
Danil Maksimov ◽  
Alexey Pavlov ◽  
Sigbjørn Sangesland
Keyword(s):  
Real Time ◽  
Barents Sea ◽  
Rock Properties ◽  
Drilling Process ◽  
Drilling Mud ◽  
Online Tool ◽  
Low Contrast ◽  
Lost Circulation ◽  
Drilling Data ◽  
Mud Loss

Abstract Heterogeneous nature and complex rock properties of carbonate reservoirs makes the drilling process challenging. One of these challenges is uncontrolled mud loss. Caves or a system of cavities could be a high-risk zone for drilling as the mud losses cannot always be controlled by conventional methods, such as mud weight (MW) / equivalent mud weight (ECD) optimization, or by increasing concentration of lost circulation material (LCM) in the drilling mud. Seismic-based detection of such karstification objects is inefficient due to relatively small size, various shapes and low contrast environment. In this paper we, based on drilling data from the Barents sea, analyzed possible patterns in real-time drilling data corresponding to drilling through karstification objects. These patterns can serve as real-time indicators of zones with higher risk of karsts and can be used as an online tool for decision support while drilling in karstified carbonates.

A Holistic Approach to Characterize Mud Loss Using Dynamic Mud Filtration Data

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Chinedum Peter Ezeakacha ◽  
Saeed Salehi
Keyword(s):  
Regression Analysis ◽  
Field Application ◽  
Operating Conditions ◽  
Mitigation Strategies ◽  
Drilling Mud ◽  
Experimental Conditions ◽  
Lost Circulation ◽  
Rotary Speed ◽  
Mud Filtration ◽  
Mud Loss

Drilling mud loss in highly porous media and fractured formations has been one of the industry's focuses in the past decades. Wellbore dynamics and lithology complexities continue to push for more research into accurate quantification and mitigation strategies for lost circulation and mud filtration. Conventional methods of characterizing mud loss with filtration data for field application can be time-consuming, particularly because of the interaction between several factors that impact mud loss and filtration. This paper presents a holistic engineering approach for characterizing lost circulation using pore-scale dynamic water-based mud (WBM) filtration data. The approaches used in this study include: factorial design of experiment (DoE), hypothesis testing, analysis of variance (ANOVA), and multiple regression analysis. The results show that an increase in temperature and rotary speed can increase dynamic mud filtration significantly. An increase in lost circulation material (LCM) concentration showed a significant decrease dynamic mud filtration. A combination of LCM concentration and rotary speed showed a significant decrease in dynamic mud filtration, while a combination of LCM concentration and temperature revealed a significant increase in dynamic mud filtration. Rotary speed and temperature combination showed an increase in dynamic mud filtration. The combined effect of these three factors was not significant in increasing or decreasing dynamic mud filtration. For the experimental conditions in this study, the regression analysis for one of the rocks showed that dynamic mud filtration can be predicted from changes in LCM concentration and rotary speed. The results and approach from this study can provide reliable information for drilling fluids design and selecting operating conditions for field application.

Real-Time Software to Estimate Friction Coefficient and Downhole Weight on Bit During Drilling of Horizontal Wells

2014 ◽  
Author(s):  
Mazeda Tahmeen ◽  
Geir Hareland ◽  
Bernt S. Aadnoy
Keyword(s):  
Friction Coefficient ◽  
Real Time ◽  
Information Transfer ◽  
Horizontal Wells ◽  
Drill String ◽  
Surface Measurement ◽  
Drilling Process ◽  
Drilling Data ◽  
Weight On Bit ◽  
Drag Analysis

The increasing complexity and higher drilling cost of horizontal wells demand extensive research on software development for the analysis of drilling data in real-time. In extended reach drilling, the downhole weight on bit (WOB) differs from the surface seen WOB (obtained from on an off bottom hookload difference reading) due to the friction caused by drill string movement and rotation in the wellbore. The torque and drag analysis module of a user-friendly real-time software, Intelligent Drilling Advisory system (IDAs) can estimate friction coefficient and the effective downhole WOB while drilling. IDAs uses a 3-dimensional wellbore friction model for the analysis. Based on this model the forces applied on a drill string element are buoyed weight, axial tension, friction force and normal force perpendicular to the contact surface of the wellbore. The industry standard protocol, WITSML (Wellsite Information Transfer Standard Markup Language) is used to conduct transfer of drilling data between IDAs and the onsite or remote WITSML drilling data server. IDAs retrieves real-time drilling data such as surface hookload, pump pressure, rotary RPM and surface WOB from the data servers. The survey data measurement for azimuth and inclination versus depth along with the retrieved drilling data, are used to do the analysis in different drilling modes, such as lowering or tripping in and drilling. For extensive analysis the software can investigate the sensitivity of friction coefficient and downhole WOB on user-defined drill string element lengths. The torque and drag analysis module, as well as the real-time software, IDAs has been successfully tested and verified with field data from horizontal wells drilled in Western Canada. In the lowering mode of drilling process, the software estimates the overall friction coefficient when the drill bit is off bottom. The downhole WOB estimated by the software is less than the surface measurement that the drillers used during drilling. The study revealed verification of the software by comparing the estimated downhole WOB with the downhole WOB recorded using a downhole measuring tool.

scholarly journals Analisis Rheologi Lumpur Lignosulfonat dengan Penambahan LCM Berbahan Serbuk Gergaji, Batok, dan Sekam Berbagai Temperatur

2018 ◽  
Vol 2 (2) ◽  
pp. 33
Author(s):  
Ryan Raharja ◽  
Sugiatmo Kasmungin ◽  
Abdul Hamid
Keyword(s):  
Laboratory Scale ◽  
Drilling Process ◽  
Drilling Mud ◽  
Rice Husks ◽  
Mud Cake ◽  
High Temperature Condition ◽  
Temperature Levels ◽  
Filtrate Loss ◽  
Coconut Shells ◽  
Mud Loss

<p><em>Kehilangan sirkulasi lumpur merupakan kejadian </em>yang sering terjadi dalam proses pemboran. Hilang lumpur yang terjadi bisa saja sebagian dari lumpur pemboran dan bahkan kehilangan lumpur pemboran secara total. Pada percobaan ini kehilangan lumpur pemboran akan diteliti dalam skala laboratorium. Dengan penambahan LCM diharapkan berguna untuk menanggulangi hilangnya lumpur tersebut. Dengan mencoba mengalirkan lumpur pada media berpori yang telah ditentukan, kehilangan lumpur akan dilihat dari seberapa besar lumpur yang hilang dalam skala laboratorium yang dibuat. Kemudian lumpur yang dibuat ditambahkan LCM berupa serbuk gergaji, batok kelapa dan sekam padi dan diteliti seberapa besar pengaruh LCM dalam mengurangi kehilangan lumpur tersebut. Campuran macam LCM lumpur tersebut juga diuji pengaruhnya terhadap beberapa tingkatan temperatur antara lain temperatur 80<sup>o</sup>F, 190<sup>o</sup>F dan 300<sup>o</sup>F, tentunya hal ini dilakukan untuk mendapatkan nilai <em>sealing </em>yang baik pada masing-masing LCM jika berada pada keadaan temperatur yang tinggi yang dikondisikan dengan kondisi sumur sebenarnya. Percobaan ini juga dilakukan untuk mengetahui <em>filtrate loss</em> yang terjadi pada berbagai macam campuran lumpur dengan LCM tersebut. Ketebalan <em>mud cake</em> yang terbentuk dalam pengukuran kehilangan filtrat juga diamati seberapa besar mud cake yang dihasilkan. Dan setelah itu reologi dari masing-masing lumpur tersebut juga diukur untuk menyimpulkan hasilnya. </p><p><em>Loss of mud circulation is an event that often occurs in the drilling process. The loss of mud that occurred could have been partly from drilling mud and even total drilling mud loss. In this experiment, drilling mud losses will be investigated on a laboratory scale. With the addition of LCM, it is hoped that this will be useful to overcome the loss of mud. By trying to flow sludge in a predetermined porous media, sludge loss will be seen from how much sludge is lost on a laboratory scale created. Then the LCM sludge was added in the form of sawdust, coconut shells and rice husks and examined how much influence the LCM had in reducing the sludge loss. The mixture of LCM sludge is also tested for its effect on several temperature levels including 80oF, 190oF and 300oF, of course this is done to get a good sealing value in each LCM if it is in a high temperature condition which is conditioned to actual well conditions. This experiment was also conducted to determine the filtrate loss that occurs in various slurry mixtures with the LCM. The thickness of the mud cake formed in the measurement of filtrate loss was also observed how much the mud cake was produced. And after that the rheology of each mud is also measured to conclude the results.</em></p>

Evaluation of Ultrasonic Methods for In-Situ Real-Time Characterization of Drilling Mud

2005 ◽  
Author(s):  
Judith Ann Bamberger ◽  
Margaret S. Greenwood
Keyword(s):  
Physical Properties ◽  
Real Time ◽  
Speed Of Sound ◽  
Direct Contact ◽  
Drilling Fluid ◽  
Drilling Process ◽  
Drilling Mud ◽  
Well Control

A real time multi-functional ultrasonic sensor system is proposed to provide automated drilling fluid monitoring that can improve the capability and development of slimhole and microhole drilling. This type of reliable, accurate, and affordable drilling fluid monitoring will reduce the overall costs in exploration and production. It will also allow more effective drilling process automation while providing rig personnel a safer and more efficient work environment. Accurate and timely measurements of drilling fluid properties such as flow rate, density, viscosity, and solid loading are key components for characterizing rate of drill penetration, providing early warning of lost circulation, and for use in real-time well control. Continuous drilling fluid monitoring enhances drilling economics by reducing the risk of costly drilling downtime, increasing production performance, and improving well control. Investigations conducted to characterize physical properties of drilling mud indicate that ultrasound can be used to provide real-time, in-situ process monitoring and control. Three types of ultrasonic measurements were evaluated which include analysis of in wall, through wall and direct contact signals. In wall measurements provide acoustic impedance (the slurry density and speed of sound product). Through wall and direct contact measurements provide speed of sound and attenuation. This information is combined to determine physical properties such as slurry density, solids concentration and can be used to detect particle size changes and the presence of low levels of gas. The measurements showed that for the frequency range investigated in-wall measurements were obtained over the slurry density range from 1500 to 2200 kg/m3 (10 to 17 pounds solids per gallon of drilling fluid). Other measurements were obtained at densities in the 1500 to 1800 kg/m3 range. These promising measurement results show that ultrasound can be used for real-time in-situ characterization of the drilling process by monitoring drilling mud characteristics.

Modeling Transient Circulating Mud Temperature in the Event of Lost Circulation and its Application in Locating Loss Zones

2014 ◽  
Author(s):  
Yuanhang Chen ◽  
Mengjiao Yu ◽  
Stefan Miska ◽  
Evren Ozbayoglu ◽  
Yongfeng Kang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Profile ◽  
Drilling Mud ◽  
Lost Circulation ◽  
Bottom Hole ◽  
Lack Of Information ◽  
Open Hole ◽  
Mud Loss ◽  
Multiple Loss ◽  
Cement Plug

Lost circulation is one of the most persistent and costly drilling problems that drilling engineers have been struggling with for decades. The main reason why some of the remedial procedures are not working as planned is the lack of information, such as the location of the loss zone. The pinpointing of the zone of loss will allow the treatment to be applied directly to the point of loss rather than to the entire open hole. This paper presents an approach to predict the location of loss zone from the transient mud circulation temperature profile altered by the mud loss. A numerical model in estimating the transient mud circulating temperature profile during a lost circulation event is developed. The temperature profile in both the flow conduits (drillpipe and annulus) are modeled using mass and energy balance. The flow rate of drilling mud decreases in the annulus above the loss zone as part of the fluids lost into the fractures, which in turn alters the heat transfer between the drillpipe, annulus, and formation. The wellbore is divided into two multiple sections, which account for single multiple loss circulation zones. Rigorous heat transfer in the formation is included. Case studies are performed and numerical solution results are presented and analyzed. According to the results, temperature alterations induced by mud loss include: 1) Declines in both bottom-hole temperature (BHT) and mud return temperature over time, and 2) Discontinuity in the first order derivative of annulus temperature with respect to depth at the location of loss zone; meanwhile, the temperature alterations are mainly controlled by the mud loss rate and location of loss. By matching the simulated results with the distributed temperature measurements at different times, the depth of the loss zone can be identified. This piece of information is important for the spotting of LCM (lost circulation material) pills, the optimization of overbalance squeezing pressure, as well as the consideration of setting the cement plug or additional casing.

The Effects of Temperature on Rheology Properties and Filtrate after Using Lemongrass as Lost Circulation Materials for Oil Based Drilling Mud

2014 ◽  
Vol 911 ◽  
pp. 243-247 ◽  
Author(s):  
N.A. Ghazali ◽  
T.A.T. Mohd ◽  
N. Alias ◽  
M.Z. Shahruddin ◽  
A. Sauki ◽  
...  
Keyword(s):  
High Temperature ◽  
Filter Press ◽  
Effect Of Temperature ◽  
Drilling Mud ◽  
Lost Circulation ◽  
Water Based ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Mud Loss ◽  
Lost Circulation Materials

Lost circulation materials (LCM) are used to combat mud loss to the reservoir formation which can cause problems during drilling operation. Difficulties in handling and costly are those challenges faced by drilling operator. Mostly LCM can work better in water based mud compared to oil based mud due to characteristic of LCM itself. Nowadays, most of operator interested in the ultra-deep water due to the limitation of reservesand deals with high temperature and high pressure conditions.Oil based mud (OBM) is more preferable in high temperature conditions compared to water based mud hence a laboratory study was carried out to investigate the effect of temperature on the performance of lemongrass with different sizes in oil based mud. The oil based mud was formulated and tested with three different temperatures which are 250oF, 275oF and 350oF. The lemongrass LCM was prepared with three different sizes which are 150 microns, 250 microns and 500 microns. The sizes distribution of LCM is one of the main contributors to the success of LCM in the formation. The oil based mud samples were tested using Fann Viscometer to determine rheology properties and HPHT Filter Press to investigate the amount of filtrate. It was found that different temperatures and sizes have great effects on the lemongrass LCM in the oil based mud. The optimum temperature for lemongrass LCM is 275oF and with the sizes of 250 microns.

scholarly journals IMPROVEMENT OF THE TECHNIQUE AND TECHNOLOGYOF BEDS ISOLATION USING THE PROFILE EXPANDABLE CASING

2016 ◽  
pp. 34-37
Author(s):  
G. S. Abdrakhmanov ◽  
A. A. Zalyatdinov
Keyword(s):  
Oil And Gas ◽  
Fluid Loss ◽  
Drilling Mud ◽  
Gas Wells ◽  
Lost Circulation ◽  
Threaded Connections ◽  
Complex Process ◽  
Oil And Gas Wells ◽  
High Fluid ◽  
Mud Loss

Drilling of oil and gas wells is a time consuming, very complex process in which there occur all sorts of complications. The most common one is drilling mud loss. During drilling of wells the control of this fluid loss problem takes about 12 % of total time. In this case, up to 60 % of materials and time is spent on isolation of fractured-cavernous beds with high fluid loss intensity which make up only 10 % of the total number of isolated zones. The use of liners with welded and threaded connections of shaped tubes enabled to completely solve the problem of lost circulation zones isolation regardless of their thickness, the borehole caving and the fluid loss intensity.

scholarly journals Optimasi Hidrolika Sumur “SH” Lapangan “U” Kalimantan Timur dengan Metode Bit Hydroulic Horse Power

2018 ◽  
Vol 2 (2) ◽  
pp. 1
Author(s):  
Sri Haryono
Keyword(s):  
Hydraulic System ◽  
Actual Data ◽  
Drilling Process ◽  
Fluid Flow Rate ◽  
Drilling Mud ◽  
East Kalimantan ◽  
Nozzle Size ◽  
Drilling Data ◽  
Drilling System ◽  
Horse Power

<p>Lapangan “U” ditempatkan di Cekungan Tarakan, yang merupakan salah satu daerah cekungan hidrokarbon Kalimantan Timur. Formasi yang ditembus oleh mata bor terdiri dari batupasir, batulanau, batulempung dan batubara. Oleh karena itu, kita perlu mengatur ulang sistem lumpur pengeboran terutama pada sistem hidrolik lumpur pengeboran. Penelitian ini bertujuan untuk mengoptimalkan sistem hidrolik dalam proses pengeboran untuk sumur “SH” Lapangan “U” menggunakan metode <em>Bit Hydraulic Horse Power (BHHP). </em>Hasil<em> </em>dari metode ini adalah untuk menentukan laju alir fluida <em>BHHP</em> yang optimal, daya tembus, ukuran nozzle, dan membandingkan parameter ini dengan data pengeboran aktual sebelum optimasi (data aktual) sehingga penetrasi proses pembentukan juga optimal. Berdasarkan data aktual dari semua pengeboran sumur ke 13 titik kedalaman harus dioptimalkan terutama dalam sistem pengeboran hidrolik dengan mengubah ukuran area aperture pada <em>nozzle</em> bor dan daya sesuai dengan perhitungan.</p><p><em><span class="tlid-translation translation" lang="en">The "U" field is located in the Tarakan Basin, which is one of the East Kalimantan hydrocarbon basin areas. The formation penetrated by the drill bit consists of sandstone, siltstone, claystone and coal. Therefore, we need to rearrange the drilling mud system, especially in the hydraulic drilling mud system. This study aims to optimize the hydraulic system in the drilling process for "SH" well "U" wells using the Bit Hydraulic Horse Power (BHHP) method. The result of this method is to determine the optimal BHHP fluid flow rate, permeability, nozzle size, and compare these parameters with actual drilling data before optimization (actual data) so that the penetration of the formation process is also optimal. Based on actual data from all wells drilling to 13 points the depth must be optimized especially in the hydraulic drilling system by changing the size of the aperture area on the drill nozzle and the power according to the calculation.</span></em></p>

Sequential Prediction of Drilling Fluid Loss Using Support Vector Machine and Decision Tree Methods

2021 ◽  
Author(s):  
Oluwatosin John Rotimi ◽  
David Nnaemeka Ukwu ◽  
Wang Zhenli ◽  
Yao Liang ◽  
Anthony A. Ameloko ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Decision Tree ◽  
Prediction Models ◽  
Drilling Fluid ◽  
Principal Component ◽  
Support Vector ◽  
Fluid Loss ◽  
Drilling Process ◽  
Drilling Mud ◽  
Lost Circulation

Abstract Machine learning methods have been applied to predict depths of fluid loss in hydrocarbon exploration.During drilling, lost circulation can be described as the unpleasant loss of all or part of drilling mud or fluid into the immediate formations or affected formation by excessive hydrostatic pressure, sufficient to fracture the formation or expand existing fractures encountered during the drilling process. In this study, we deployed Python codes of Support Vector Machine (SVM) and Decision Tree (DT) methodsto categorical data obtained from drilling operations in a producing field to predict lost circulation occurrence. The modelsleveraged the capability of both SVM and DT to achieve binary classification by adopting flow-out percentage of less than 70 percent as the points of lost circulation. That is, &lt; 70% is represented as Loss and &gt; 70% represented asNo Loss. Prediction models were applied to 10 input variables preprocessed with principal component analysis (PCA) to reduce dimensionality and focus on essential variables. The preprocessed SVM model gave an improved result while preprocessing does not affect DT models. Overall, DT models predicted accurate fluid losszones and can be scaled up to field operations with options ofcontinuous sampled variables.

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