scholarly journals Effect of Cleaning the Annular Space on the Adhesion of the Cement Sheath to the Rock

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5187
Author(s):  
Marcin Kremieniewski ◽  
Sławomir Błaż ◽  
Stanisław Stryczek ◽  
Rafał Wiśniowski ◽  
Andrzej Gonet
Keyword(s):  
Drilling Fluid ◽  
Research Work ◽  
Rock Surface ◽  
Gas Flows ◽  
Gas Migration ◽  
Test Results ◽  
Annular Space ◽  
Rock Formation ◽  
Mud Cake ◽  
Cement Sheath

Drilling boreholes in gas zones and in zones with the possibility of migration or gas exhalation requires a high index of well tightness. An important parameter determining the effectiveness of sealing the annular space is the adhesion of the cement sheath to the rock formation. Low values of adhesion of the cement sheath to the rock formation and to the casing surface result in the formation of uncontrolled gas flows. The lack of adhesion also reduces the stabilization of the pipe column. To obtain the required adhesion, the annular space should be properly cleaned. Thorough removal of filter cake from the drilling fluid increases adhesion and reduces gas migration from the annular space. Therefore, in this work, the authors focus on determining the effect of cleaning the annular space on the adhesion of the cement sheath to the rock formation. The results of the research work allow for further research on the modification of spacers and cement slurries in order to obtain the required increase in adhesion. The article presents the issues related to the preparation of the borehole for cementing by appropriate cleaning of the rock formation from the residue of the mud cake. During the implementation of the works, tests of cleaning the rock surface are performed. The obtained results are correlated with the results of adhesion on the rock–cement sheath cleaned of the wash mud cake contact. When analyzing the obtained test results, a relationship is found between the cleaning of the rock surface and the adhesion of the cement sheath to it.

scholarly journals Porównanie wyników metod pomiaru skuteczności usuwania osadu płuczkowego

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (1) ◽  
pp. 34-46
Author(s):  
Marcin Kremieniewski ◽  
Keyword(s):  
Fluid Flow ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Measurement Methods ◽  
Annular Space ◽  
Drilling Mud ◽  
Mud Cake ◽  
Incomplete Removal ◽  
Cement Sheath ◽  
Flow Drilling

The proper cleaning of the annular space before cementing is one of the most important factors affecting the proper sealing of the casing column. Inadequate or incomplete removal of the mud cake or residues of the mud may result in the formation of uncontrolled gas outflows (migration or exhalation) at the contact of the cement sheath with the rock formation and with the surface of run-down casing. It is related to the lack of compatibility in the contact of the mud and the cement. Additionally, the lack of proper cleaning of the annular space will reduce the adhesion value of the cement sheath to the contact surface. The result of the above may be the lack of adequate stabilization of the column of pipes due to its weakened connection in the lower part with the wall, and in the upper part with the previous column of larger diameter pipes. Therefore, to improve both the tightness of the borehole as well as the quality of the cementation condition, laboratory tests of the efficiency of cleaning the annular space are carried out by measuring the efficiency of washing mud removal. So far, measuring the efficiency of mud removal or the effect of washing utilization have been done using a rotary viscometer. During the test, a mud cake is produced on the rotor surface and then removed with washing liquid. Recently, the Oil and Gas Institute – National Research Institute developed a new method for measuring the efficiency of drilling mud removal by using a newly developed drilling fluid flow simulator (Patent P.423842). The device enables the simulation of the drilling fluid flow (drilling fluid, washing fluid, spacer) in the simulated annular space. It is possible to select the parameters of the flow (delivery rate) and the contact time of the liquid with the tested surface. Due to the different measurement principles during the tests with the viscometer and the simulator, it was decided to conduct a comparison and determine the degree of convergence of the discussed methods. The same rinsing liquids were tested to remove the same type of mud, but using different measurement methods. The obtained values of mud removal efficiency were subjected to the correlation analysis, which made it possible to compare the results of the analyzed measurement methods.

scholarly journals Comparison of Efficient Ways of Mud Cake Removal from Casing Surface with Traditional and New Agents

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3653
Author(s):  
Marcin Kremieniewski ◽  
Rafał Wiśniowski ◽  
Stanisław Stryczek ◽  
Paweł Łopata
Keyword(s):  
Reference Sample ◽  
Gas Flows ◽  
Gas Migration ◽  
Annular Space ◽  
Cement Slurry ◽  
Rotational Viscometer ◽  
New Agents ◽  
Mud Cake ◽  
Rotor Surface ◽  
Cake Removal

The tightness of the casing-rock formation interface is one of the most important elements of drilling and cementing jobs. In the absence of the required tightness, there is a risk of gas migration directly to the ground, groundwater or atmosphere. In order to eliminate this type of uncontrollable and unfavorable gas flows, the casing column is sealed with cement slurry in the annular space or beyond casing. Cement slurry displaces mud present in the annular space, although the mud cake cannot be completely removed, which is required for obtaining proper binding of cement slurry with the casing surface and the surface of the drilled formation. Therefore, it is important to prepare the well and remove the mud cake from the annular space with spacer fluid. An occasional lack of wellbore tightness requires continuous improvement of the cementing technology. Accordingly, analyses are conducted on mud cake removal with modified or new spacer fluids. Properly designed fluid should efficiently clean the surface of the casing and of the rock mass. One of the basic measurements is the analysis of the efficiency of mud cake removal from the surface of a rotational viscometer. The efficiency of traditional and newly designed fluids for mud cake removal from the casing surface with new and traditional agents has been compared further in this paper. The methodology of mud cake removal with the use of a rotational viscometer was also presented. Tests were performed for various concentrations of agents already used for spacer fluids and for a group of new agents. The efficiency of annular space cleaning was determined on the basis of a comparison with the results obtained for the reference sample, i.e., water which was used for mud cake removal from the rotor surface. The analysis of the results of experiments created bases for the comparison of the efficiency of the analyzed spacer fluids and finding the most suitable ones for mud cake removal from casing columns.

scholarly journals Utilization of metakaolin-based geopolymer as a mud-cake solidification agent to enhance the bonding strength of oil well cement–formation interface

2020 ◽  
Vol 7 (2) ◽  
pp. 191230
Author(s):  
Yuhuan Bu ◽  
Rui Ma ◽  
Jiapei Du ◽  
Shenglai Guo ◽  
Huajie Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Bonding Strength ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Research Work ◽  
Drilling Fluids ◽  
Oil Well ◽  
Mud Cake ◽  
Calculation Methodology ◽  
Zonal Isolation

This research work designed a novel mud-cake solidification method to improve the zonal isolation of oil and gas wells. The calculation methodology of mud-cake compressive strength was proposed. The optimal formula of activator and solid precursors, the proper activating time and the best activator concentration were determined by the compressive strength test. The effects of solid precursors on the properties of drilling fluid were evaluated. Test results show that the respective percentage of bentonite, metakaolin, slag and activator is 1 : 1 : 0.3 : 0.8, as well as the optimum ratio of Na 2 SiO 3 /NaOH is 40 : 1. The optimum concentration of activator is 0.21 and the activating time should be more than 10 min. The solid precursors did not show any bad influence on the rheological property of drilling fluids. Even though the compressive strength decreased when the solid precursors blended with barite, the strength values can still achieve 8 MPa. The reaction of metakaolin and activator formed cross-link structure in the mud-cake matrix, which enhanced the connection of the loose bentonite particles, lead to the significant enhancement of shear bonding strength and hydraulic bonding strength. This mud-cake solidification method provides a new approach to improve the quality of zonal isolation.

Solidifying Mud Cake to Improve Cementing Quality of Shale Gas Well: A Case Study

2015 ◽  
Vol 8 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Jun Gu ◽  
Ju Huang ◽  
Su Zhang ◽  
Xinzhong Hu ◽  
Hangxiang Gao ◽  
...  
Keyword(s):  
Shale Gas ◽  
Calcium Silicate Hydrate ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Gas Well ◽  
Safety Requirements ◽  
Mud Cake ◽  
Gas Bearing

The purpose of this study is to improve the cementing quality of shale gas well by mud cake solidification, as well as to provide the better annular isolation for its hydraulic fracturing development. Based on the self-established experimental method and API RP 10, the effects of mud cake solidifiers on the shear strength at cement-interlayer interface (SSCFI) were evaluated. After curing for 3, 7, 15 and 30 days, SSCFI was remarkably improved by 629.03%, 222.37%, 241.43% and 273.33%, respectively, compared with the original technology. Moreover, the compatibility among the mud cake solidifier, cement slurry, drilling fluid and prepad fluid meets the safety requirements for cementing operation. An application example in a shale gas well (Yuanye HF-1) was also presented. The high quality ratio of cementing quality is 93.49% of the whole well section, while the unqualified ratio of adjacent well (Yuanba 9) is 84.46%. Moreover, the cementing quality of six gas-bearing reservoirs is high. This paper also discussed the mechanism of mud cake solidification. The reactions among H3AlO42- and H3SiO4- from alkali-dissolved reaction, Na+ and H3SiO4- in the mud cake solidifiers, and Ca2+ and OH- from cement slurry form the natrolite and calcium silicate hydrate (C-S-H) with different silicate-calcium ratio. Based on these, SSCFI and cementing quality were improved.

Modelling of Flow Properties of Asphalt Mastics

2013 ◽  
Vol 752 ◽  
pp. 209-216 ◽  
Author(s):  
Róbert Géber ◽  
László A. Gömze
Keyword(s):  
Research Work ◽  
Road Construction ◽  
Test Results ◽  
Flow Properties ◽  
Rheological Models ◽  
Fine Grained ◽  
Mineral Particles ◽  
Asphalt Mastics ◽  
Rheological Modelling ◽  
Mineral Fillers

The present research work deals with the examination and rheological modelling of flow properties of asphalt mastics which are the most important components of asphalt concretes. Asphalt mastics are mixtures of fine grained mineral filler particles (d<0,063 mm) and bitumen, having a stabilizing role in asphalt mixtures and largely determining the cohesion between mineral particles and bitumen. During our examinations two types of mineral fillers – limestone and dolomite – as well as standard bitumen were tested, which are extensively used in Hungarian road construction. Asphalt mastic mixtures were prepared out of these materials and they were tested with dynamic shear rheometer (DSR). According to the test results, rheological models of mastics were determined. It has been established that at different test temperatures and shear rate ranges asphalt mastics behave as Herschel-Bulkley and Bingham-type materials.

scholarly journals Study on Thermo-Hydro-Mechanical Coupling and the Stability of a Geothermal Wellbore Structure

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 649
Author(s):  
Xiaolin Huan ◽  
Gao Xu ◽  
Yi Zhang ◽  
Feng Sun ◽  
Shifeng Xue
Keyword(s):  
Effective Stress ◽  
Cold Water ◽  
Drilling Fluid ◽  
Water Injection ◽  
Coupled Model ◽  
In Situ Stress ◽  
Excess Pore Pressure ◽  
Mechanical Coupling ◽  
Open Hole ◽  
Cement Sheath

For processes such as water injection in deep geothermal production, heat transfer and fluid flow are coupled and affect one another, which leads to numerous challenges in wellbore structure safety. Due to complicated wellbore structures, consisting of casing, cement sheaths, and formations under high temperature, pressure, and in situ stress, the effects of thermo-hydro-mechanical (THM) coupling are crucial for the instability control of geothermal wellbores. A THM-coupled model was developed to describe the thermal, fluid, and mechanical behavior of the casing, cement sheath, and geological environment around the geothermal wellbore. The results show that a significant disturbance of effective stress occurred mainly due to the excess pore pressure and temperature changes during cold water injection. The effective stress gradually propagated to the far-field and disrupted the integrity of the wellbore structure. A serious thermal stress concentration occurred at the junction of the cased-hole and open-hole section. When the temperature difference between the injected water and the formation was up to 160 °C, the maximum hoop tensile stress in the granite formation reached up to 43.7 MPa, as high as twice the tensile strength, which may increase the risk of collapse or rupture of the wellbore structure. The tensile radial stress, with a maximum of 31.9 MPa concentrated at the interface between the casing and cement sheath, can cause the debonding of the cementing sheath. This study provides a reference for both the prediction of THM responses and the design of drilling fluid density in geothermal development.

A gas migration law study of a large-scale 3D physical similarity simulation with an adaptive Kalman filter algorithm

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuyu Hao ◽  
Shugang Li ◽  
Tianjun Zhang
Keyword(s):  
Kalman Filter ◽  
Large Scale ◽  
Gas Migration ◽  
Adaptive Kalman Filter ◽  
Physical Similarity ◽  
Content Type ◽  
Gas Concentration ◽  
Rock Formation ◽  
Concentration Estimation ◽  
Migration Law

Purpose In this study, a physical similarity simulation plays a significant role in the study of crack evolution and the gas migration mechanism. A sensor is deployed inside a comparable artificial rock formation to assure the accuracy of the experiment results. During the building of the simulated rock formation, a huge volume of acidic gas is released, causing numerous sensor measurement mistakes. Additionally, the gas concentration estimation approach is subject to uncertainty because of the complex rock formation environment. As a result, the purpose of this study is to introduce an adaptive Kalman filter approach to reduce observation noise, increase the accuracy of the gas concentration estimation model and, finally, determine the gas migration law. Design/methodology/approach First, based on the process of gas floatation-diffusion and seepage, the gas migration model is established according to Fick’s second law, and a simplified modeling method using diffusion flux instead of gas concentration is presented. Second, an adaptive Kalman filter algorithm is introduced to establish a gas concentration estimation model, taking into account the model uncertainty and the unknown measurement noise. Finally, according to a large-scale physical similarity simulation platform, a thorough experiment about gas migration is carried out to extract gas concentration variation data with certain ventilation techniques and to create a gas chart of the time-changing trend. Findings This approach is used to determine the changing process of gas distribution for a certain ventilation mode. The results match the rock fissure distribution condition derived from the microseismic monitoring data, proving the effectiveness of the approach. Originality/value For the first time in large-scale three-dimensional physical similarity simulations, the adaptive Kalman filter data processing method based on the inverse Wishart probability density function is used to solve the problem of an inaccurate process and measurement noise, laying the groundwork for studying the gas migration law and determining the gas migration mechanism.

Enhancement lubricity properties of water-based mud with nanoparticles

2020 ◽  
pp. 70-74
Author(s):  
V.V. Guliyev ◽  
◽  
◽  
Keyword(s):  
Yield Point ◽  
Coefficient Of Friction ◽  
Drilling Fluid ◽  
Research Work ◽  
Shear Thinning ◽  
Rheological Parameters ◽  
Drilling Process ◽  
Drilling Mud ◽  
Pseudoplastic Fluid ◽  
Water Based

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.

Comparative Analysis of the Rheological Behaviour of Irvingia Gabonensis Ogbono and Foreign Polymer for Bentonite Formulated Mud.

2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
David Ekuma ◽  
Ikechukwu Okafor ◽  
Innocent Nweze
Keyword(s):  
Rheological Properties ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Research Work ◽  
Rheological Behaviour ◽  
Oil And Gas Industry ◽  
Drilling Mud ◽  
Gas Industry ◽  
Local Product ◽  
Irvingia Gabonensis

Abstract Drilling fluid are complex fluids consisting of several additives. These additives are added to enhance and control the rheological properties (such as viscosity, gel strength and yield point) of the mud. These properties are controlled for effective drilling of a well. This research work is focused on determining the rheological behavior of drilling mud using industry-based polymer and Irvingia Gabonensis (ogbono) as viscosifiers. Water based muds were formulated from the aforementioned locally sourced viscosifier and that of the conventional used viscosifier (Carboxylmetyl cellulose, CMC). Laboratory tests were carried out on the different muds formulated and their rheological properties (such as yield stress, shear stress, plastic viscosity and shear rate) are evaluated. The concentration of the viscosifiers were varied. The expected outcome of the research work aims at lowering the total drilling cost by reducing the importation of foreign polymer which promotes the development of local content in the oil and gas industry. The research compares the rheology of mud samples and the effect of varying the concentration (2g, 4g, 6g, 8g, and 10g) of both CMC and Ogbono and determining the changes in their rheological properties. The total volume of each mud sample is equivalent to 350ml which represent one barrel (42gal) in the lab. From the result, at concentration of 2g, the ogbono mud has a better rheology than the CMC mud, but at a concentration above 2g, CMC mud shows a better rheology than ogbono mud, that is, as the concentration of CMC is increased, the rheological properties of the mud increased while as the concentration of ogbono is increased the rheological properties decreased. The viscosity of the drilling fluid produced from the ogbono were lower than that of CMC, it could be used together with another local product such as cassava starch, offor or to further improve the rheology and then be a substitute to the conventional viscosifiers.

EFFECT OF WET-DRY CYCLING ON BOND BEHAVIOR OF GFRP STRENGTHENED HISTORIC MASONRY STRUCTURES

2016 ◽  
Vol 78 (5-2) ◽  
Author(s):  
Meng Jing ◽  
Werasak Raongjant
Keyword(s):  
Research Work ◽  
Fiber Reinforced Polymer ◽  
Masonry Structures ◽  
Test Results ◽  
Bond Behavior ◽  
Historic Masonry ◽  
Water Permeation ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Cycling Condition

The objective of this research work is to determine the effect of wet-dry cycling on bond behavior of historic masonry structures strengthened by Glass Fiber Reinforced Polymer (GFRP). Shear bond testing was carried out through total 36 specimens exposed to dry, full moisture or wet-dry cycling conditions.  The selected samples were then tested at 0, 30, 60 and 90 days. Post-ageing test was also preceded on total sixty masonry prisms exposed to dry, full moisture or wet-dry cycling conditions. The compressive strengths of selected samples were then tested at 0, 40, 70 and 100 days. The test results showed an obvious decrease of the bond strength between GFRP sheets and bricks in the wet-dry cycling condition. For masonry prisms with or without GFRP strengthening, in the first 40 days, the compressive strength of GFRP bonded prism decreased quickly to the value near that of prism without GFRP. After 40 days the rate of decrease became slow, which means that, sheets retrofitted outside the masonry prisms helped to improve their durability by reducing water permeation. 

Sign in / Sign up

Export Citation Format

Share Document