scholarly journals Effects of Drilling Mud Properties on Hydrate Dissociation Around Wellbore during Drilling Operation in Hydrate Reservoir

2022 ◽  
Vol 35 (1) ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1185-1198
Author(s):  
Qingchao Li ◽  
Lingling Liu ◽  
Baohai Yu ◽  
Linian Guo ◽  
Sheng Shi ◽  
...  

AbstractBorehole collapse will pose a threat to the safety of equipment and personnel during drilling operation. In this paper, a finite element multi-field coupling model for investigating borehole collapse in hydrate reservoir was developed. In this model, fluid seepage, heat transfer, hydrate dissociation and borehole deformation are all considered. Based on which, effects of drilling fluid density on both of hydrate dissociation and borehole collapse are investigated. The investigation results show that disturbance of drilling fluid invasion to hydrate reservoir will lead to hydrate dissociation around wellbore, and dissociation range narrows obviously with the increase in drilling fluid density. When the relative fluid density is 0.98, natural gas hydrates in reservoir with a width of about 16.65 cm around wellbore dissociate completely. However, dissociation range of natural gas hydrate has decreased to 12.08 cm when the relative fluid density is 1.10. Moreover, hydrate dissociation around wellbore caused by drilling fluid invasion may lead to borehole collapse, and borehole collapse can be significantly restrained with the increase in relative fluid density. Borehole enlargement rate is 33.67% when the relative fluid density is 0.98, but nearly no collapse area displays around wellbore when the relative fluid density increases to 1.12. In addition, investigation herein can provide an idea for designing drilling fluid density in hydrate reservoir when different allowable borehole enlargement rate is considered. The minimum fluid density designed for avoiding disastrous borehole collapse increases nonlinearly when higher requirements for borehole stability are proposed.


2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Osei H

High demand for oil and gas has led to exploration of more petroleum resources even at remote areas. The petroleum resources are found in deeper subsurface formations and drilling into such formations requires a well-designed drilling mud with suitable rheological properties in order to avoid or reduce associated drilling problems. This is because rheological properties of drilling muds have considerable effect on the drilling operation and cleaning of the wellbore. Mud engineers therefore use mud additives to influence the properties and functions of the drilling fluid to obtain the desired drilling mud properties especially rheological properties. This study investigated and compared the impact of barite and hematite as weighting agents for water-based drilling muds and their influence on the rheology. Water-based muds of different concentrations of weighting agents (5%, 10%, 15% and 20% of the total weight of the drilling mud) were prepared and their rheological properties determined at an ambient temperature of 24ᵒC to check their impact on drilling operation. The results found hematite to produce higher mud density, plastic viscosity, gel strength and yield point when compared to barite at the same weighting concentrations. The higher performance of the hematite-based muds might be attributed to it having higher specific gravity, better particle distribution and lower particle attrition rate and more importantly being free from contaminants. The water-based muds with hematite will therefore be more promising drilling muds with higher drilling and hole cleaning efficiency than those having barite.


2019 ◽  
Vol 3 (1) ◽  
pp. 50
Author(s):  
Zakky Zakky ◽  
Bayu Satyawira ◽  
Samsol Samsol

Mud is one of the things that is very supportive in drilling operations, the design of the mud can affect the effectiveness of drilling work, the costs to be incurred, up to when the well is in production. Of course what is expected from a mud usage is low expenditure and drilling with optimal results. Drilling mud plays a very important role in a drilling operation. Drilling that can run quickly, safely and economically is greatly influenced by the conditions and sludge system used. The condition referred to here is how the properties or rheology of the mud. Whereas the mud system referred to here is a certain type of mud that must be used with regard to the state of the formation and borehole. Muddy KCl-POLYMER is a non-dispersed mud, where the hydration and dispersion process of the shale formation drilled must be maintained or maintained as much as possible. There are several ways to achieve this, the most common of which is to limit the amount of water that reacts with the shale, by covering the cutting produced by the shale with the polymer as soon as possible to prevent further reactions with water. In this study, we will analyze the use and physical properties of drilling mud using KCl-Polymer sludge which is carried out in the Trisakti University Laboratory of Petroleum Drilling and Production.


2021 ◽  
Vol 230 ◽  
pp. 01007
Author(s):  
Ivan Vargas-Cordero de la Cruz ◽  
Michela Giustiniani ◽  
Umberta Tinivella ◽  
Giulia Alessandrini

In last decades, the Chilean margin has been extensively investigated to better characterize the complex geological setting through the acquisition of geophysical data and, in particular, seismic lines. The analysis of seismic lines allowed identifying the occurrence of gas hydrates and free gas in many places along the margin. Clearly, the gas hydrate reservoir could be a strategic energy reserve for Chile, but, on the other hand, the dissociated of gas hydrate due to climate change could be an issue to face. Moreover, this region is characterized by large and mega-scale earthquakes that may contribute to gas hydrate dissociation and consequent submarine slides triggering. In this context, Chilean margin should be considered a natural laboratory to study the hydrate system evolution.


2020 ◽  
Vol 10 (8) ◽  
pp. 3389-3397 ◽  
Author(s):  
Nayem Ahmed ◽  
Md. Saiful Alam ◽  
M. A. Salam

Abstract Loss of drilling fluid commonly known as mud loss is considered as one of the critical issues during the drilling operation as it can cause severe formation damage. To minimize fluid loss, researchers introduced numerous additives but did not get the expected result. Recently, the use of nanoparticles (NPs) in drilling fluid gives a new hope to control the fluid loss. A basic KCl–Glycol–PHPA polymer-based mud is made, and six different concentrations of 0.1, 0.5, 1.0, 1.5, 2.0, 3.0 wt% iron (III) oxide or Hematite (Fe2O3) NPs are mixed with the basic mud. The experimental observations reveal that fluid loss of basic mud is 5.9 ml after 30 min and prepared nano-based drilling mud results in a less fluid loss at all concentrations. Nanoparticles with a concentration of 0.5 wt% result in a 5.1 ml fluid loss at the API LTLP filter press test. On the other hand, nanoparticles with a concentration of 3.0 wt% enhance the plastic viscosity, yield point, and 10 s gel strength by 15.0, 3.0, and 12.5%, respectively. The optimum concentration of hematite NPs is found to be 0.5 wt% which reduces the API LPLT filtrate volume and filter cake thickness by 13.6 and 40%, respectively, as well as an improvement of plastic viscosity by 10%.


2011 ◽  
Vol 366 ◽  
pp. 378-387 ◽  
Author(s):  
Fu Long Ning ◽  
Yi Bing Yu ◽  
Guo Sheng Jiang ◽  
Xiang Wu ◽  
Ke Ni Zhang ◽  
...  

When drilling through the oceanic gas hydrate-bearing sediments, the water-based mud under overbalanced drilling condition will invade into the borehole sediments. The invasion behavior can influence the hydrate stability, wellbore stability and well logging evaluation. In this work, we performed the numerical simulations to study the effects of density (i.e., corresponding pressure), temperature and salinity of mud on the mud invasion and hydrate stability around borehole. The results show that the mud invasion will promote greatly the hydrate dissociation near wellbore sediments if the temperature of mud is higher than that of hydrate stability. Under certain conditions, the higher mud density, temperature and salinity, the greater degree of mud invasion and heat transfer, and the more hydrate dissociation. The gas produced from hydrate dissociation can reform hydrates again in the sediments, and even the hydrate saturation is higher than that in situ sediments due to the displacing effect of the mud invasion, which forms a high-saturation hydrate girdle band around the borehole.


2019 ◽  
Vol 8 (4) ◽  
pp. 9720-9722

Drilling fluid or mud is essential fluid in drilling operation which has many important properties and one of the important properties is the viscosity of the drilling fluid and the viscosity is further classified as yield viscosity and plastic viscosity which means different in terms of its function. This paper is attempting to show the rheological characteristics of the different samples of the drilling fluid using Xanthan Gum and Physillum husk and different weighting agents Barite and Calcium Carbonate at ambient conditions. The results showed that xanthan gum acts as good viscosifying agent as compared with physillum husk. In addition that, the water based drilling mud with barite which act as weighing agent proved better as compared with calcium carbonate. The following paper will be valuable to the graduates, future graduates and also to the Industry personnel have a basic idea about the rheology and how the parameters related to the rheology are valuable in mud design.


Author(s):  
Zhizeng Xia ◽  
Jian Hou ◽  
Xuewu Wang ◽  
Xiaodong Dai ◽  
Mingtao Liu

The cyclic methane hydrate production method was proposed with CO2 and N2 mixture stimulation. The cyclic production model was established based on actual hydrate reservoir parameters, accordingly, the production characteristics were analyzed, and a sensitivity analysis was conducted. The results show the following: (1) The depressurization mechanism is dominant in the cyclic production. CH4 production and CH4 hydrate dissociation can be greatly enhanced because the cyclic process can effectively reduce the partial pressure of CH4 (gas phase). However, there is a limited effect for CO2 storage. (2) Heat supply is essential for continuous hydrate dissociation. The CH4 hydrate dissociation degree is the highest in the near-wellbore area; in addition, the fluid porosity and effective permeability are significantly improved, and the reservoir temperature is obviously decreased. (3) The initial CH4 hydrate saturation, absolute permeability, intrinsic CO2 hydrate formation kinetic constant, injection time and production time can significantly influence the production performance of the natural gas hydrate reservoir.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Akash K. Gupta ◽  
Rahul Yadav ◽  
Malay K. Das ◽  
Pradipta K. Panigrahi

Purpose This paper aims to present the implementation of a multi-layer radiation propagation model in simulations of multi-phase flow and heat transfer, for a dissociating methane hydrate reservoir subjected to microwave heating. Design/methodology/approach To model the induced heterogeneity due to dissociation of hydrates in the reservoir, a multiple homogeneous layer approach, used in food processes modelling, is suggested. The multi-layer model is incorporated in an in-house, multi-phase, multi-component hydrate dissociation simulator based on the finite volume method. The modified simulator is validated with standard experimental results in the literature and subsequently applied to a hydrate reservoir to study the effect of water content and sand dielectric nature on radiation propagation and hydrate dissociation. Findings The comparison of the multi-layer model with experimental results show a maximum difference in temperature estimation to be less than 2.5 K. For reservoir scale simulations, three homogeneous layers are observed to be sufficient to model the induced heterogeneity. There is a significant contribution of dielectric properties of sediments and water content of the reservoir in microwave radiation attenuation and overall hydrate dissociation. A high saturation reservoir may not always provide high gas recovery by dissociation of hydrates in the case of microwave heating. Originality/value The multi-layer approach to model microwave radiation propagation is introduced and tested for the first time in dissociating hydrate reservoirs. The multi-layer model provides better control over reservoir heterogeneity and interface conditions compared to existing homogeneous models.


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