A Rotational Continuous-Circulation Tool RCCT for Decreasing Non-Productive Time NPT and Mitigating Drilling Operational Risk

2021 ◽  
Author(s):  
Meshari Mansour Alshalan ◽  
Amjad O. Alshaarawi ◽  
Haytham H. Alhamed ◽  
Abdulwahab S. Aljohar

Abstract This work presents how a Rotational Continuous-Circulation Tool (RCCT) can decrease non-productive time and mitigate risks in the oil and gas drilling operations. The proposed tool provides almost continuous rotation of the drill-string and continuous circulation of drilling mud during the making/breaking of drill-pipe connections. Continuous rotation minimizes the stationary time during the connection. Thus, the risk of static contact between the wall of the formation and drill string (which can cause a differentially stuck drill-pipe) is reduced. This is one aspect by which non-productive time (NPT) is reduced, and the potential of encountering a differentially stuck pipe incident is mitigated. Continuous circulation enhances the hole cleaning efficiency. Rather than gravitating or being suspended, drilling cuttings continue to be removed to surface during connections with continuous circulation. As a result, the risk of having a mechanical stuck pipe incident (e.g., Pack-off) is prevented. In addition, maintaining continuous circulation eliminates down-hole pressure fluctuations. This reduces the risk of hole stability issues, and also enables navigation through zones with tight drilling pressure window. The proposed tool has been trial-tested twice to demonstrate its compatibility with the current drilling rigs/practices. Further trial tests are planned to demonstrate the added value of the tool.

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure


2021 ◽  
Vol 261 ◽  
pp. 02021
Author(s):  
Xiaoyong Yang ◽  
Shichun Chen ◽  
Qiang Feng ◽  
Wenhua Zhang ◽  
Yue Wang

With the increasing intensity of oil and gas field exploration and development, oil and gas wells are also drilling into deeper and more complex formations. Conventional steel drilling tools can no longer meet the requirements of ultra-deep, high-temperature and high-pressure wells. The paper first analyzes the advantages of titanium alloy drill pipe based on basic performance of titanium alloy drill pipe. The experimental results show that the basic properties of titanium alloy drill pipes meet the operating standards of the petroleum industry. Then the buckling performance of titanium alloy drill pipe and steel drill pipe is compared, the calculation results show that the buckling performance of titanium alloy drill tools is slightly lower than that of steel drill tools. Secondly, the maximum allowable buildup rate of titanium alloy drill pipe and steel drill tool is studied. The research shows that under the same condition of the drill pipe outer diameter, titanium alloy drill pipe can be used for a smaller curvature radius and greater buildup rate. This advantage of titanium alloy drill pipe makes it more suitable for short radius and ultra-short radius wells. Finally, taking a shale gas horizontal well as an example, with the goal of reducing drill string friction and ensuring drill string stability, a comparative study on the application of titanium alloy drill pipe and steel drill pipe is carried out. The results show that titanium alloy drill pipe has a wider application in the field, and is suitable for operations under various complex working conditions.


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 300 ◽  
pp. 04004
Author(s):  
Edris Hassan ◽  
Jamil Abdo ◽  
Jan Kwak ◽  
Abdullah Al Shabibi

Drilling is one of the costliest activities in oil and gas industry due to the complexity of interactions with downhole rock formation. Under such conditions, the uncertainty of drillstring behaviour increase and hence it becomes difficult to predict the causes, occurrences, and types of failures. Lateral and torsional vibrations often cause failure of Bottom Hole Assembly (BHA), drillstring failure, drill bit and wall borehole damages. In this work, a model is presented to determine the impact of lateral and torsional vibrations on a drillstring during the drilling operation. The model aims to mimic real drillstring behaviour inside a wellbore with regards to its dynamic movements due to multiple real situations such as eccentricity of collars, drill pipe sections, and stick-slip phenomena occurring due to the interaction of the bit and the drillstring with the well formation. The work aims to develop a basis for determining critical operating speeds and design parameters to provide safe drilling procedures and reduce drill string fatigue failure. Lagrangian approach is used in this study to attain drillstring lateral and torsional vibration coupling equations. The nonlinear equations are solved numerically to obtain the response of the system. In this work, we also present a brief description of an in-house constructed experimental setup. The setup has the capability to imitate the downhole lateral and torsional vibration modes. Parameters from the experimental investigations are incorporated for validation of the mathematical models and for prediction of the drillstring fatigue life. Such investigations are essential for oil and gas industries as they provide solutions and recommendations about operational speed, lateral and torsional amplitudes measurements and corrections, and the conditions for avoiding occurrence of natural frequencies of the system.


2021 ◽  
pp. 1-11
Author(s):  
Ahmed K. Abbas ◽  
Mortadha T. Alsaba ◽  
Mohammed F. Al Dushaishi

Abstract Extended reach (ERD) wells with a horizontal and highly deviated section are widely applied in the oil and gas industry because they provide higher drainage area than vertical wells; and hence, increase the productivity or injectivity of the well. Among many issues encountered in a complex well trajectory, poor hole cleaning is the most common problem, which occurs mainly in the deviated and horizontal section of oil and gas wells. There are significant parameters that have a serious impact on hole cleaning performance in high-angle and horizontal sections. These include flow rate, rheology and density of the drilling fluid, drillstring eccentricity, pipe rotation, and cuttings size. It has been recognized that the action of most of these parameters to transport drilled cuttings is constantly a point of controversy among oilfield engineers. In the present study, extensive experiments were conducted in an advanced purpose-built flow rig to identify the main parameters affecting on circulate the cuttings out of the test section in a horizontal position. The flow-loop simulator has been designed to allow easy variation of operational parameters in terms of flow rate, mud density, drillstring eccentricity, pipe rotation, and cuttings size. In addition, the study covers the impacts of laminar, transition, and turbulent flow regimes. The goal of such variation in the operational conditions is to simulate real field situations. The results have shown that drill string rotation and flow rate were the operational parameters with the highest positive influence on the cuttings transports process. In contrast, drill pipe eccentricity has a negative influence on cuttings removal efficiency. The cuttings transportation performance is further improved by pipe rotation at different levels of eccentricity, especially at fully eccentric annuli. It was also shown that larger cuttings appeared to be easier to remove in a horizontal annulus than smaller ones. The experimental results would provide a more in-depth understanding of the relationship between drilling operation parameters and hole cleaning efficiency in ERD operations. This will help the drilling teams to realize what action is better to take for efficient cutting transportation.


2021 ◽  
Author(s):  
Mohammad J. Ahsan ◽  
Shaikha Al-Turkey ◽  
Nitin M. Rane ◽  
Fatemah A. Snasiri ◽  
Ahmed Moustafa ◽  
...  

Abstract Objectives/Scope The acquisition of mud gas data for well control and gathering of geological information is a common practice in oil and gas drilling. However, these data are scarcely used for reservoir evaluation as they are presumably considered as unreliable and non-representative of the formation content. Recent development in gas extraction from drilling mud and analyzing equipment has greatly improved the data quality. Combined with proper analysis and interpretation, these new datasets give valuable information in real-time lithological changes, hydrocarbons content, water contacts and vertical changes in fluid over a pay interval. Methods, Procedures, Process Post completion, Mud logging data have been compared with PVT results and they have shown excellent correlation on the C1-C5 composition, confirming the consistency between gas readings and reservoir fluid composition. Having such information in real time has given the oil company the opportunity to optimize its operations regarding formation evaluation, e.g downhole sampling, wireline logging or testing programs. Formation fluid is usually obtained during well tests, either by running downhole tools into the well or by collecting the fluid at surface. Therefore, its composition remains unknown until the arrival of the PVT well test results. This case intends to use mud gas information collected while drilling to predict information about the reservoir fluid composition in near real time. To achieve this goal we compared mud gas data collected while drilling with reservoir fluid compositional results. Pressure volume temperature (PVT) analysis is the process of determining the fluid behaviors and properties of oil and gas samples from existing wells. Results, Observations, Conclusions The reason any oil and gas company decides to drill a well is to turn the project into an oil-producing asset. But the value of the oil extracted from a single well is not the same as the value of the oil produced from another. The makeup of the oil, which can be determined from the compositional analysis, is an important piece of the equation that determines how profitable the play will be. The compositional analysis will determine just how much of each type of petroleum product can be produced from a single barrel of oil from that wells. Novel/Additive information Formation samples were obtained from offset wells in the Marrat Formation. These datasets gave valuable indications on fluid properties and phase behavior in the reservoir and provided strong base for reservoir engineering analysis, simulation and surface facilities design. The comparison of the gas data to PVT results gives a good match for reservoir fluid finger print, early acquisition of this data will help for decision enhancement for field development.


Author(s):  
Parham Pournazari ◽  
Pradeepkumar Ashok ◽  
Eric van Oort

This paper presents a robust control algorithm for automatic hoisting of a drill string in oil and gas drilling operations. We demonstrate an iterative scheme for trajectory design and present a lumped dynamic model of the hoisting system. The trajectory is used along with the dynamic model to design a hybrid sliding mode and gain scheduled PI controller to deal with the frictional nonlinearities of the system. The simulation results demonstrate the feasibility of this approach in optimally performing the pipe hoisting task.


Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 79-87
Author(s):  
Yevhen KHARCHENKO ◽  
Andrii HUTYI ◽  
Volodymyr HAIDUK

A mathematical model and the computer software for the analysis of dynamic processes occurring in the drilling pipes in the borehole under stuck drill string release by means of an impact mechanism (a jerking device) or a pulse-wave installation, equipped with electric linear pulse motor are presented. The drill string with an impact mechanism, which is inserted over the stuck section after failure, is detected and is activated by lowering and taking the non-stuck upper part of the string by means of the drilling rig drive and is considered as a discrete-continuous mechanical system. As a result of the impact of the hammer on the body of the impact mechanism, wave processes are formed in the drill string, which helps to release the stuck drill string. The influence of friction forces on propagation of longitudinal waves in the drill pipe string is investigated. Practical recommendations are developed regarding the above-mentioned efficiency of drilling for oil and gas.


2018 ◽  
Vol 148 ◽  
pp. 16005 ◽  
Author(s):  
Wei Lin ◽  
Yang Liu

Stick-slip oscillation in drill-string is a universal phenomenon in oil and gas drilling. It could lead to the wear of drill bit, even cause catastrophic failure of drill-strings and measurement equipment. Therefore, it is crucial to study drilling parameters and develop appropriate control method to suppress such oscillation. This paper studies a discrete model of the drill-string system taking into account torsional degree-of-freedom, drill-string damping, and highly nonlinear friction of rock-bit interaction. In order to suppress the stick-slip oscillation, a new proportional-derivative controller, which can maintain drill bit’s rotation at a constant speed, is developed. Numerical results are given to demonstrate its efficacy and robustness.


Author(s):  
S Mok ◽  
D G Gorman

This paper examines the correlation between volumetric wear loss and the energy expended at the interface of nitrile rubber sliding on steel in the presence of drilling mud and abrasive sand. The measurement of energy expended at the material interface is investigated as an alternative for monitoring the extent of wear damage due to operating conditions. This is contrasted with running hours, as is typical of reciprocating mud pumps used in oil and gas drilling operations. It is found that increased deterioration and wear loss resulted from the combined effects of load and sand. The volumetric wear loss was found to increase at the rate of 16.8 per cent per 1 per cent sand and is specific to the type of sand used and the test configuration employed.


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