scholarly journals Mathematical Simulation of Lost Circulation in Fracture and Its Control

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiao Cai ◽  
Boyun Guo ◽  
Qingfeng Guo ◽  
Hongwei Jiang
Keyword(s):  
Numerical Model ◽  
Drilling Fluid ◽  
Control Process ◽  
Practical Method ◽  
Analytical Models ◽  
Sensitivity Analyses ◽  
Circulation Control ◽  
High Concentration ◽  
Lost Circulation ◽  
Lost Circulation Materials

Lost circulation has been one of the major problems that impede efficient and cost-saving drilling operations. The nature of lost circulation and its control is not yet fully understood. A method to characterize the mud loss in fracture and the plugging process of lost circulation materials is highly desired to obtain a thorough understanding of mud losses in fracture and provide reference for lost circulation control. This paper presents an easy-to-use method to identify types of lost circulation in fracture and the corresponding control. Three analytical models are presented based on three loss mechanisms, namely, seepage/filtration in a fracture, pipe flow in a fracture, and gravity displacement in a fracture. A numerical model is developed to simulate the deposition of lost circulation materials in fractures and predict the time and the volume of drilling fluid needed for lost circulation control. Case studies with these analytical models provide a deeper insight of this subject. Sensitivity analyses with the numerical model identify the major factors responsible for lost circulation control. High viscosity of drilling fluid may prevent lost circulation, while low viscosity is desired for a fast control of lost circulation. Lowering the density of drilling fluid is another way to prevent the lost circulation and facilitate the deposition of lost circulation materials. Lost circulation materials with high density could deposit faster close to the wellbore and therefore accelerating the control process. High concentration of lost circulation materials is likely to shorten the plugging time, which should be determined referring to the severity of loss. This work provides drilling engineers a practical method for simulating the lost circulation and selecting lost circulation material.

Risk Planning and Mitigation in Oil Well Fields

2015 ◽  
Vol 4 (4) ◽  
pp. 27-48
Author(s):  
Nediljka Gaurina-Međimurec ◽  
Borivoje Pašić ◽  
Petar Mijić
Keyword(s):  
Preventive Measures ◽  
Drilling Fluid ◽  
Oil Well ◽  
Remedial Measures ◽  
Successful Management ◽  
Lost Circulation ◽  
Wellbore Strengthening ◽  
Lost Circulation Materials ◽  
Industry Experience ◽  
Tools And Methods

Lost circulation presents one of the major risks associated with drilling. The complete prevention of lost circulation is impossible but limiting circulation loss is possible if certain precautions are taken. Industry experience has proved that is often easier and more effective to prevent the occurrence of loss than to attempt to stop or reduce them once they have started. The problem of lost circulation was magnified considerably when operators began drilling deeper and/or depleted formations. A strategy for successful management of lost circulation should include preventative (best drilling practices, drilling fluid selection, and wellbore strengthening materials) and remedial measures when lost circulation occurs through the use of lost circulation materials. In this paper the authors present lost circulation zones and causes, potential zones of lost circulation, excessive downhole pressures causes, preventive measures, tools and methods for locating loss zones and determining the severity of loss, lost circulation materials, and recommended treatments.

Managing Suspension Characteristics of Lost-Circulation Materials in a Drilling Fluid

2016 ◽  
Vol 30 (04) ◽  
pp. 310-315 ◽  
Author(s):  
Sandeep D. Kulkarni ◽  
Dale E. Jamison ◽  
Kushabhau D. Teke ◽  
Sharath Savari
Keyword(s):  
Drilling Fluid ◽  
Lost Circulation ◽  
Lost Circulation Materials

Investigation into Permeability and Bearing Strength of Plugging Zone Formed by Lost Circulation Materials

2012 ◽  
Vol 190-191 ◽  
pp. 504-508
Author(s):  
Song Li ◽  
Yi Li Kang ◽  
Li Jun You ◽  
Da Qi Li
Keyword(s):  
Calcium Carbonate ◽  
Drilling Fluid ◽  
Soap Film ◽  
Fracture Width ◽  
Lost Circulation ◽  
Bearing Strength ◽  
Confining Pressures ◽  
Mud Loss ◽  
Lost Circulation Materials ◽  
Relationship Of

Mud loss while drilling fractured formations is a major problem for drilling operating. It is a key to successful temporary sealing technology that lost circulation materials (LCM) can quickly form the plugging zone in the fractures. The permeability of plugged zone influences its bearing strength, as drilling fluid can penetrate and break it, causing it destabilizing and then failure of lost circulation controlling. With the soap film flowmeter, designing different LCM under variable confining pressures, considering the matching relationship of grain diameters and fracture width is (0.5～1):1, analyzing the permeability of plugging zones with different materials. The results indicated that permeability of plugging zone with peanut grains is lower than that of calcium carbonate, but its bearing strength is not as good as that of calcium carbonate, while using merely single LCM. Comparing other materials, the ideal plugging zone is formed with the mixture of peanut grains and calcium carbonate, which has the lowest permeability as well as the bearing strength. The mixture of matching calcium carbonate and smaller peanut grains, comparing to the width of fracture could stands 5 MPa of pressure difference at normal temperature, and 3.9 MPa at 80°C temperature in laboratory. To some extent, it can meet the needs of temporary sealing technology and successfully deal with lost circulation, which demands plugged tightly and bilateral pressurization.

Wood Fibre Based Lost Circulation Materials

2018 ◽  
Author(s):  
Arild Saasen ◽  
Helge Hodne ◽  
Egil Ronæs ◽  
Simen André Aarskog ◽  
Bente Hetland ◽  
...  
Keyword(s):  
Fibre Type ◽  
Drilling Fluid ◽  
Wood Fibre ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
Bottom Hole Assembly ◽  
Induced Fractures ◽  
Fine Wood ◽  
Lost Circulation Materials

In this paper both a coarse and fine wood fibre type of Lost Circulation Material (LCM) is tested in the laboratory. It is shown how these fibre treatments work. The fibre type is partially oil wetting making them suitable for application in oil based drilling fluids. The fine material helps stopping small drilling induced fractures, while the coarse helps stopping lost circulation into several natural fractures or coal or conglomerate formations. In the article, the selection of wood fibres is described in more detail. Testing of the fine materials were conducted conventionally by pumping drilling fluid volumes with LCM onto slotted disks in fluid loss apparatuses. The coarse fibres are too large to be tested in these apparatuses. Therefore, gravel with grain diameter around two centimetres was filled into transparent cylinders. The pore throats created by these gravel particles were above half a centimetre. For both of these LCMs the experiments show the sensitivity of the LCM concentration in the drilling fluid to stop the lost circulation. Also, it is shown the effect of the LCM on viscous properties of the drilling fluids. Not all LCMs can be pumped through the bit. The article describes the need for circulation subs in the bottom hole assembly (BHA) to hinder the LCM blocking the entire BHA.

scholarly journals Evaluation of some natural water-insoluble cellulosic material as lost circulation control additives in water-based drilling fluid

2015 ◽  
Vol 24 (4) ◽  
pp. 461-468 ◽  
Author(s):  
Ahmed Mohamed Alsabagh ◽  
Mahmoud Ibrahim Abdou ◽  
Hany El-sayed Ahmed ◽  
Ahmed Abdel-salam Khalil ◽  
Amany Ayman Aboulrous
Keyword(s):  
Natural Water ◽  
Drilling Fluid ◽  
Circulation Control ◽  
Cellulosic Material ◽  
Lost Circulation ◽  
Water Based

scholarly journals Laboratory Study on a New Composite Plugging Material with High Bearing Strength and High-Temperature Resistance

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Xiaoming Su ◽  
Zhanghua Lian ◽  
Hanqiao Xiong ◽  
Yuan Yuan ◽  
Junwei Fang
Keyword(s):  
High Temperature ◽  
Drilling Fluid ◽  
Carbonate Reservoir ◽  
Invasion Depth ◽  
Temperature Resistance ◽  
Lost Circulation ◽  
Bearing Strength ◽  
High Temperature Resistance ◽  
Acid Solubility ◽  
Lost Circulation Materials

The reservoir in the Central Tarim Basin is a typical high-pressure fracture-vuggy carbonate reservoir with high temperatures, which easily leads to drilling fluid losses and the high-temperature carbonate. The conventional lost circulation materials (LCMs) cannot meet the reservoir. To resolve this problem, a rigid particle with high-temperature resistance, high acid solubility, and high rigidity was developed, tested, and evaluated. According to bridge rules of 1/2–2/3 opening degree of formation fracture, the formulation experiments of GZD and other lost circulation materials were conducted and a novel composite lost circulation material (LCM) was completed. Lastly, we investigated the compatibility of LCM and mud in site though compatibility experiment, analyzed the plugging effect of the system for fracture and vuggy by laboratory static lost circulation simulation and evaluation and sand-bed plugging experiments, respectively. The results show that compared with the conventional rigid lost material, the value of high-temperature resistance is more and acid solubility is over 98%. Also, it can work well with other fiber materials (E), variable filling particles (F and G), and superfine filling particles (H) and form a novel plugging material, named MGY-I, whose temperature resistance value is more than 473.15 K, the bearing strength is over than 9 MPa, the mud filtrate invasion depth of sand bed made from coarse particles (10∼20 mesh) is only 3.0 cm within 30 minutes, and the invasion depth is less than 1 cm within 30 minutes when the sand bed is made from 80∼100 mesh. The optimal concentrations of rigid granule, lignin fiber, elastic particle, and superfine calcium carbonate are 8% (A : B : CD = 2 : 1 : 1), 0.5%, 6%, and 1%, respectively. And, the plugging function of “GZD-rigidity bridge and filling, fiber network and deformable filing” is better exerted on the formation fracture with a high loading capacity and a high-temperature resistance.

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