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

Author(s):  
Ryan Raharja ◽  
Sugiatmo Kasmungin ◽  
Abdul Hamid

<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>

Author(s):  
Danil Maksimov ◽  
Alexey Pavlov ◽  
Sigbjørn Sangesland

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.


2021 ◽  
Vol 10 (2) ◽  
pp. 94-100
Author(s):  
Idham Khalid ◽  
Novia Rita ◽  
Muhammad Efras

Drilling is an activity carried out to obtain the desired target. Furthermore, drilling mud a very significant material involved in the drilling process, and must, therefore, obtain a rational value from the rheology. A suitable technique to achieve this goal is the use of additives, for instance, Carboxymethyl Cellulose (CMC) to improve the viscosity and air binding. This study, therefore, uses CMC produced from organic oil palm bunches as an alternative for industrial CMC. CMC of Oil Palm Empty Bunches have been tested by Energy Dispersive X-ray Spectroscopy (EDS) to determine its composition. The Empty Oil Palm Oil which uses Tenera type was taken from Riau Province, Rokan Hulu Regency, Kunto Darussalam District. In this study, this experiment used CMC Empty Oil Palm and industrial CMC to find the value of viscosity, plastic thickness, melting point, gel strength, mud cake, and filtering volume of drilling mud and prevent the loss circulation with adding each CMC composition to mud samples with amount of 2 gr, 4 gr, 6 gr, 8 gr and 10 gr. According to the EDS analysis, the Carbon (C) and Oxygen (O) content of CMC from empty oil palm bunches were 58.85% and 41.15%, respectively. In addition, the industrial standard for plastic viscosity and yield point were not attained by using 8 gr and 10 gr of this CMC.


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.


2021 ◽  
Author(s):  
Chee Phuat Tan ◽  
Wan Nur Safawati Wan Mohd Zainudin ◽  
M Solehuddin Razak ◽  
Siti Shahara Zakaria ◽  
Thanavathy Patma Nesan ◽  
...  

Abstract Drilling in permeable formations, especially depleted reservoirs, can particularly benefit from simultaneous wellbore shielding and strengthening functionalities of drilling mud compounds. The ability to generate simultaneous wellbore shielding and strengthening in reservoirs has potential to widen stable mud weight windows to drill such reservoirs without the need to switch from wellbore strengthening compound to wellbore shielding compound, and vice-versa. Wellbore shielding and strengthening experiments were conducted on three outcrop sandstones with three mud compounds. The wellbore shielding stage was conducted by increasing the confining and borehole pressures in 4-5 steps until both reached target pressures. CT scan images demonstrate consistency of the filtration rates with observed CT scanned mud cakes which are dependent on the sandstone pore size and mud compound particle size distributions. In wellbore strengthening stage, the borehole pressure was increased until fracture was initiated, which was detected via borehole pressure trend and CT scan imaging. The fractures generated were observed to be plugged by mud filter solids which are visible in the CT scan images. The extent of observed fracture solid plugging varies with rock elastic properties, fracture width and mud compound particle size distribution. Based on the laboratory test data, fracture gradient enhancement concept was developed for the mud compounds. In addition, the data obtained and observations from the tests were used to develop optimal empirical design criteria and guidelines to achieve dual wellbore strengthening and shielding performance of the mud compounds. The design criteria were validated on a well which was treated with one of the mud compounds based on its mud loss events during drilling and running casing.


2014 ◽  
Vol 625 ◽  
pp. 626-629 ◽  
Author(s):  
Mandy Su Zan Gui ◽  
Seyed Amirmostafa Jourabchi ◽  
Hoon Kiat Ng ◽  
Suyin Gan

Slow pyrolysis (SP) and fast pyrolysis (FP) of rice husks, coconut shells and their mixtures were studied in a fixed bed reactor. The objectives of this study were to compare the yields and properties of bio-oils produced using SP and FP methods within a pyrolysis temperature range of 400 °C to 600 °C. Three different biomass compositions, 100% rice husks (RH), 100% coconut shells (CS) and a mixture of 50% rice husks with 50% of coconut shells (RH50/CS50) were experimented. In SP, the maximum yield of bio-oil for RH, CS and RH50/CS50 were 45.45%, 37.01%, 38.29% at temperatures of 550 °C, 500 °C and 600 °C respectively. As for FP, the maximum bio-oil yield obtained for RH, CS and RH50/CS50 were 50.52%, 40.14% and 42.25% at temperatures of 500 °C, 600 °C and 550 °C respectively. At these optimum pyrolysis temperatures, the percentage differences in bio oil yields for SP and FP were 10.57%, 8.11% and 9.83% for RH, CS and RH50/CS50 respectively. Based on American Society for Testing and Materials (ASTM) standard procedures, the properties of bio-oil were characterised and it was found that the bio oil produced by FP at optimum temperatures were less acidic, higher density, lower water content and viscosity as compared to the bio-oil produced by SP method for all biomass compositions.


2021 ◽  
Author(s):  
Raymond Saragi ◽  
Mohammad Husien ◽  
Dalia Salim Abdullah ◽  
Ryan McLaughlin ◽  
Ian Patey ◽  
...  

Abstract A study was carried out to examine formation damage mechanisms caused by drilling fluids in tight reservoirs in several onshore oil fields in Abu Dhabi. Three phases of compatibility corefloods were carried out to identify potential to improve hydrocarbon recovery and examine reformulated/alternate drilling muds and treatment fluids. Interpretation was aided by novel Nano-CT quantifications and visualisations. The first phase examined the current drilling muds and showed inconsistent filtrate loss control alongside high levels of permeability alteration. These alterations were caused by retention of drilling mud constituents in the near-wellbore and incomplete clean-up of drilling mud-cakes. Based upon these results, reformulated and alternate drilling muds were examined in Phase 2, and there was a positive impact upon both filtrate loss and permeability, although the Nano-CT quantifications and visualisations showed that drilling mud constituents were still having an impact upon permeability. Candidate treatment fluids were examined in Phase 3, with all having a positive impact and the best performance coming from 15% HCl and an enzyme-based treatment. The interpretative tools showed that these treatments had removed drilling mud-cakes, created wormholes, and bypassed the areas where constituents were retained. The compatibility corefloods on tight reservoir core, alongside high-resolution quantifications and visualisations, therefore identified damaging mechanisms, helped identify potential to improve hydrocarbon recovery, and identify treatment fluid options which could be used in the fields.


2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Chinedum Peter Ezeakacha ◽  
Saeed Salehi

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.


1972 ◽  
Vol 3 (3) ◽  
pp. 33
Author(s):  
B.M. Haines ◽  
D.W. Emerson

In order that the whole suite of geophysical logging methods may be employed, it is necessary that the borehole contain drilling mud. Usually in shallow water bores this mud consists simply of a clay component and make-up water, although during drilling it also contains particles and fluids derived from the formations penetrated. The major purposes of the mud, from the driller's point of view, are to lubricate and cool the bit, to prevent caving especially in unconsolidated sediments and to carry bit cuttings to the surface. While the mud composition may be relatively simple, the physical, electrical and chemical system comprising the mud column and formation is rather complex. Mud filtrate, a fluid extract of the mud, is expressed and enters the formations under the influence of differential hydrostatic pressure; consequently, a mud cake is formed on the borehole walls; and the filtrate itself provides electrochemical contrasts with the formation waters. The system is further complicated by the frequently unsystematic approach to the specification and control of drilling mud, and the general lack of understanding of the system as a dynamic entity. The volume of influence of all well logging methods therefore includes drilling mud, mud cake, invaded and uninvaded formation, these latter being wholly or partially saturated by filtrate and formation water respectively. For purposes of quantitative log interpretation, especially in regard to electrical logs, it is a necessary prerequisite that the electrical properties of the mud and its derivatives be either measured directly, or derived through established relationships with readily measured properties. A limited laboratory experimental study has indicated the relationships between the electrical and physical properties of the mud system and the influence of solids content. Field testing of these relationships showed that they are extensively modified in both form and magnitude by formation particles and waters acquired during drilling. It is apparent that relationships are strongly dependent on several factors, and should be evaluated separately for individual borehole/mud/formation systems.


Author(s):  
Eghe Oyedoh ◽  
Charles Odumugbo ◽  
Eboseremen Osemenkhian Ebewele

The oil production industry in Nigeria operates both onshore and more recently offshore in the coastal areas located in the oil-rich Niger-Delta. Unfortunately, the drilling mud additives currently used in the country are all imported and at huge foreign exchange costs. Therefore the objective of the current effort is development of drilling fluid from locally sourced mud additives for drilling operations. Various rheological and filtration tests were carried out on both unbeneficiated and beneficiated local clay from Afuze, Nigeria using a six-speed Rheometer and API filter press respectively. Beneficiation involved the addition of sodium carbonate, caustic soda and starch to the mud formulations.Clay concentrations were varied from 20g/350ml to 60g/350ml. The test results showed that free swell volume (FSV) increased from with clay concentration with the optimum values observed at 60g/350ml. The filtrate loss of 63ml, filter cake thickness of 6m, yield point of 7cp and plastic viscosity of 1cp values of Afuze clay did not satisfy API specification of 15ml, 2m, 24cp and 8cp respectively at any tested concentration. Likewise Afuze clay did not display gel strength (10 seconds and 10 minutes of 29 and 34 respectively) suitable for bringing cuttings up from the hole. However, improvements in its rheological and filtration properties as well as free swell volume were observed with the beneficiated Afuze clay at clay concentrations of 20, 30, 40, 50, 60g/350ml when beneficiated with starch concentrations of 1g and 0.5g, sodium carbonate of 2g and 1g and caustic soda of 0.25g. Beneficiated Afuze clay displayed gel strengths (10 seconds and 10 minutes of 98 and 140 respectively) suitable for bringing cuttings up from the hole with optimum values observed at 60g/350ml.


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.


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