Well Control Research and Development

Author(s):  
Paulo R. Ribeiro ◽  
Otto L. A. Santos

Well control has been an inexhaustible source of research/development/innovation for the past four decades due to its impact in oil and gas exploration and production. Such an importance is based on three pillars: i) human safety, ii) environmental protection, and iii) economic issues. Macondo incident has proved that continuing development of the subject is an issue to be tackled by oil companies to preserve and also rebuild their image to society. One of the most important aspects of well control is the development of kick simulators capable of handling increasing complexity of well geometry (diameters and trajectory), drilling fluids (synthetic drilling fluid), well location (land and offshore) and wellbore conditions (increasing pressure and temperature severity with depth). Such simulators have the following missions: i) to help the drilling engineer to make decisions during well control procedures and kick situations, ii) to provide personnel training and certification and iii) to guarantee a better understanding and interpretation of field observations. The main objectives of the present work are three-fold: i) to present an overview of the evolution of kick modeling and simulation over the years, ii) to focus on the R&D efforts of the joint work of academia and industry to build a well control model to handle deep and ultra-deepwater drilling challenges and iii) to present a software based on that model to assist drilling engineers during well control operations. Experimental data has been based on PVT measurements of gas and synthetic drilling fluid mixtures under HPHT conditions. Phase behavior modeling has proved to be a very important issue to be taken into account in the two-phase flow model that represents the kick circulation process. The current work presents the results of the interaction of experimental lab work and numerical modeling to develop a kick simulator to handle complex drilling scenarios to assist drilling personnel in well control operations.

2014 ◽  
Vol 802 ◽  
pp. 262-267 ◽  
Author(s):  
Marina Seixas Pereira ◽  
Ronaldo de Andrade Martins ◽  
André Leibsohn Martins ◽  
Marcos Antônio de Souza Barrozo ◽  
Carlos Henrique Ataíde

Oil companies have increasingly invested in alternative technologies for cuttings treatment. The research for new operations or equipments leads to investigate the properties and characteristics of drilled cuttings and drilling fluids. This work presents the physical characterization of cuttings, drilling fluid and organic phase recoved after cuttings drying. It was carried out analysis of rheology for the drilling fluid and particle size and shape for the cuttings. Considering the microwave drying technology, which has been investigated for cuttings treatment, it was also determined the dielectric properties for the drilling fluid. The quality of the organic phase recovered in the microwave cuttings drying was also analysed.


Author(s):  
Gilles Numkam ◽  
Babak Akbari

Abstract Global energy demand continues to drive oil and gas exploration in increasingly challenging environments. The extreme temperatures and pressures drilling fluids are subjected to require optimum design of their rheology. Among the numerous components used in the design of drilling fluids are surfactants. Surfactants play an important role in the emulsification of immiscible liquids as well as the alteration of cuttings wettability to facilitate transport to the surface. Nonionic surfactants, depending on their chemical group allow the inversion of oil-in-water emulsions (O/W) to water-in-oil (W/O) and vice-versa depending on the direction of temperature change. In this study, emulsion-suspension samples were prepared with different nonionic surfactants at Oil:Water ratios of 50:50 and 60:40. The mechanical properties of the samples was assessed using a scientific rheometer at temperatures ranging from 0–90 °C. Phase inversion from oil-in-water to water-in-oil was observed for samples stabilized by polyoxyethylene oleyl ether surfactants. Build up in the apparent viscosity of the samples was observed following phase inversion, mainly resulting from the formation of nanosized dispersed water droplets. Findings in the study highlighted the possibility of obtaining different drilling fluid types during downhole circulation, thereby paving a path for the design optimization of drilling fluids used in offshore operations.


2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Pingting Liu ◽  
Zhiyu Huang ◽  
Hao Deng ◽  
Rongsha Wang ◽  
Shuixiang Xie

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent (SDA), as a novel surfactant for treatment of waste oil-based drilling fluid, was synthesized by amine, formic acid, and formaldehyde solution. With this agent, the waste oil-based drilling fluid can be treated without complex process and expensive equipment. Furthermore, the agent used in the treatment can be recycled, which reduces waste of resource and energy. The switch performance, deoiling performance, structural characterization, and mechanisms of action are studied. The experimental results show that the oil content of the recycled oil is higher than 96% and more than 93% oil in waste oil-based drilling fluid can be recycled. The oil content of the solid residues of deoiling is less than 3%.


Author(s):  
E.A. Flik ◽  
◽  
Y.E. Kolodyazhnaya

The article assesses the environmental safety of drilling fluids that are currently widely used in the oil and gas industry. It shows active development of water-based drilling fluid systems using xanthan biopolymer.


Author(s):  
Raj Kiran ◽  
Saeed Salehi

Pushing the boundaries of oil and gas exploration and development to new frontiers have led to exposure and more significant uncertainties, which necessitates robust strategies and techniques. With the increasing water depth, longer risers, and harsh pressure and temperature conditions; the risk of riser gas getting undetected get bigger. The lack of an integrated system to anticipate the controlling parameters at the choke below the BOP constrains the tackling operations and exacerbate the side effects of oil and gas well blowouts. This leads to an urgent need for an extensive study to address the riser gas unloading (RGU) events. This study encompasses the development of a robust model that can characterize the effect of different parameters such as temperature, mud types, back pressure, and solubility in RGU events. It also presents comparative results of oil-based and water-based mud systems, using a novel tool based on analytical and numerical models. The analytical model is constructed using combined gas law, heat transfer mechanism, and gas solubility and bubble point pressure concepts. Results suggest that the oil-based mud (OBM) takes more time for gas unloading in comparison to the water-based mud. Also, a significant deviation was observed in unloading patterns while considering temperature effect. For the drilling fluid without temperature consideration, the gas unloading occur in a smaller span of time and at a higher depth. Overall, this paper will demonstrate the effect of different parameters affecting the gas unloading in the riser, and present a comparative study of different parameters using an analytical which can be used in the field to get an idea of gas prior to any response for abnormality.


Author(s):  
Bunyami Shafie ◽  
Lee Huei Hong ◽  
Phene Neoh Pei Nee ◽  
Fatin Hana Naning ◽  
Tze Jin Wong ◽  
...  

Drilling mud is a dense, viscous fluid mixture used in oil and gas drilling operations to bring rock cuttings to the earth's surface from the boreholes as well as to lubricate and cool the drill bit. Water-based mud is commonly used due to its relatively inexpensive and easy to dispose of. However, several components and additives in the muds become increasingly cautious and restricted. Starch was introduced as a safe and biodegradable additive into the water-based drilling fluid, in line with an environmental health concern. In this study, the suitability of four local rice flours and their heat moistures derivatives to be incorporated in the formulation of water-based drilling fluid was investigated. They were selected due to their natural amylose contents (waxy, low, intermediate, and high). They were also heat moisture treated to increase their amylose contents. Results showed that the addition of the rice flours into water-based mud significantly reduced the density, viscosity, and filtrate volume. However, the gel strength of the mud was increased. The rice flours, either native or heat moisture treated, could serve as additives to provide a variety of low cost and environmentally friendly drilling fluids to be incorporated and fitted into different drilling activity.


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.


2019 ◽  
Vol 18 (3) ◽  
pp. 1321-1350 ◽  
Author(s):  
James Cust ◽  
Torfinn Harding

AbstractWe provide evidence that institutions have a strong influence over where oil and gas exploration takes place. We utilise a global data set on the location of exploration wells and national borders. This allows for a regression discontinuity design with the identifying assumption that the position of borders was determined independently of geology. In order to break potential simultaneity between borders, institutions, and activities in the oil sector, we focus on drilling that occurred after the formation of borders and institutions. Our sample covers 88 countries over the 1966–2010 period. At borders, we estimate more than twice as much drilling on the side with better institutional quality. Subsample analyses reveal effects of institutions on exploration drilling in both developing and high income countries, as well as across three types of operating companies. We find that the supermajor international oil companies are particularly sensitive to institutional quality in developing countries. Our findings are consistent with the view that institutions shape both exploration companies’ incentives to invest in drilling and host countries’ supply of drilling opportunities.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Felipe Chagas ◽  
Paulo R. Ribeiro ◽  
Otto L. A. Santos

Abstract The demand for energy has increased recently worldwide, requiring new oilfield discoveries to supply this need. Following this demand increase, challenges grow in all areas of the petroleum industry especially those related to drilling operations. Due to hard operational conditions found when drilling complex scenarios such as high-pressure/high-temperature (HPHT) zones, deep and ultradeep water, and other challenges, the use nonaqueous drilling fluids became a must. The reason for that is because this kind of drilling fluid is capable to tolerate these extreme drilling conditions found in those scenarios. However, it can experience changes in its properties as a result of pressure and temperature variations, requiring special attention during some drilling operations, such as the well control. The well control is a critical issue since it involves safety, social, economic, and environmental aspects. Well control simulators are a valuable tool to support well control operations and preserve the well integrity, verifying operational parameters and to assist drilling engineers in the decision-making process during well control operations and kick situations. They are also important computational tools for rig personnel training. This study presents well control research and development contributions, as well as the results of a computational well control simulator that applies the Driller's method and allows the understanding the thermodynamic behavior of synthetic drilling fluids, such as n-paraffin and ester base fluids. The simulator employed mathematical correlations for the drilling fluids pressure–volume–temperature (PVT) properties obtained from the experimental data. The simulator results were compared to a test well data set as well to the published results from other kick simulators.


2020 ◽  
Vol 7 (2) ◽  
pp. 191230
Author(s):  
Yuhuan Bu ◽  
Rui Ma ◽  
Jiapei Du ◽  
Shenglai Guo ◽  
Huajie Liu ◽  
...  

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.


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