Design and Experimental Validation of Nonlinear Infinite-Dimensional Adaptive Observer in Automated Managed Pressure Drilling

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Agus Hasan ◽  
Lars Imsland ◽  
Espen Hauge
Keyword(s):  
Flow Rate ◽  
Drilling Fluid ◽  
Drill String ◽  
Adaptive Observer ◽  
Well Control ◽  
Infinite Dimensional ◽  
Parameter Estimations ◽  
Managed Pressure Drilling ◽  
Process Measurements ◽  
Available Information

Utilizing flow rate and pressure data in and out of the fluid circulation loop provides a driller with real-time trends for early detection of well-control problems that impact the drilling efficiency. Due to limited number of sensors and time delay in processing and measurements, the flow rate and pressure along the annulus and drill string need to be estimated. This paper presents state and parameter estimations for infinite-dimensional models used in automated managed pressure drilling (MPD). The objective is to monitor the key process variables associated with process safety by designing a nonlinear adaptive observer that use the available information coming from the continuous-time online process measurements at the outlet of the well. The adaptive observer consists of a copy of the infinite-dimensional model plus output injection terms where the gain is computed analytically in terms of the Bessel function of the first kind. The design is tested using field data from a drilling commissioning test by Statoil ASA, Stavanger, Norway. The results show that the nonlinear adaptive observer estimates the flow rate and pressure of the drilling fluid accurately.

Prediction of Cuttings Transport Behavior under Drill String Rotation Conditions in High-Inclination Section

2020 ◽  
Vol 34 (10) ◽  
pp. 2059035
Author(s):  
Shihui Sun ◽  
Jinyu Feng ◽  
Zhaokai Hou ◽  
Guoqing Yu
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Drilling Fluid ◽  
Drill String ◽  
Additional Contribution ◽  
Fluid Viscosity ◽  
Fluid Flow Rate ◽  
Cuttings Transport ◽  
Hole Cleaning ◽  
Cuttings Bed

Cuttings are likely to accumulate and eventually form a cuttings bed in the highly-deviated section, which usually lead to high friction and torque, slower rate of penetration, pipe stuck and other problems. It is therefore necessary to study cuttings transport mechanism and improve hole cleaning efficiency. In this study, the cuttings-transport behaviors with pipe rotation under turbulent flow conditions in the highly deviated eccentric section were numerically simulated based on Euler solid–fluid model and Realizable [Formula: see text]–[Formula: see text] model. The resulted numerical results were compared with available experimental data in reported literature to validate the algorithm, and good agreement was found. Under the conditions of drill string rotation, cuttings bed surface tilts in the direction of rotation and distributes asymmetrically in annulus. Drill string rotation, drilling fluid flow rate, cuttings diameter, cuttings injection concentration and drilling fluid viscosity affect the axial velocity of drilling fluid; whereas drilling fluid tangential velocity is mainly controlled by the rotational speed of drill string. Increase in value of drill string rotation, drilling fluid flow rate or hole inclination will increase cuttings migration velocity. Notably, drill string rotation reduces cuttings concentration and solid–fluid pressure loss, and their variations are dependent on inclination, cuttings injection concentration, cuttings diameter, drilling fluid velocity and viscosity. However, when a critical rotation speed is reached, no additional contribution is observed. The results can provide theoretical support for optimizing hole cleaning and realizing safety drilling of horizontal wells and extended reach wells.

scholarly journals Research on Overflow Monitoring Mechanism Based on Downhole Microflow Detection

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Liang Ge ◽  
Ze Hu ◽  
Ping Chen ◽  
Lei Shi ◽  
Qing Yang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Flow Measurement ◽  
Drilling Fluid ◽  
Rate Variation ◽  
Lost Circulation ◽  
Bottom Hole ◽  
Managed Pressure Drilling ◽  
Type Flow ◽  
Drilling System ◽  
The Cost

The flow rate variation of the drilling fluid and micro-overflow loss is difficult to analyze. The purpose to prevent the occurrence of kick, lost circulation, and other complex conditions is not easy to be achieved. Therefore, the microflow-induced annulus multiphase flow rate and annulus pressure field model were studied, and a downhole microflow measurement system has been developed. A differential pressure type flow measurement was used in the system, and real-time downhole information was obtained to achieve deep, narrow windows and other safety-density complex formation security. This paper introduced a new bottom-hole flow meter which can measure the annular flux while drilling and monitor overflow and circulation loss. The accuracy and reliability of the MPD (managed pressure drilling) system can be improved obviously by applying the device; as a result, the safety of drilling is enhanced and the cost is reduced.

Nitrogen-Based Back Pressure Unit Modernizes Managed Pressure Drilling Operations

2021 ◽  
Author(s):  
Wamidh Louayd Al-Hashmy
Keyword(s):  
Drilling Fluid ◽  
Pressure Control ◽  
Drill String ◽  
Back Pressure ◽  
Managed Pressure Drilling ◽  
Core Function ◽  
Wellbore Pressure ◽  
Drilling Operations ◽  
Pressure Unit ◽  
Static Conditions

Abstract Managed Pressure Drilling (MPD) solutions are no longer the anomaly to Operator strategies, but rather another tool in their belts. With this continual utilization, MPD is evolving to become compact, more effective and safer. The inventive use of a Nitrogen Backup Unit (NBU) has eliminated the reliance of MPD operations on sizable Auxiliary Pumps. The core function of MPD operations is maintaining the total wellbore pressure by manipulating surface applied back pressure. MPD relies on circulating fluid as back pressure is generated by restricting flow against its choke(s). While drilling, fluid circulation is a given; however, that is not the case during static conditions such as drill string connections. The NBU solves this issue by injecting a small volume of nitrogen into the MPD lines upstream of the choke at a pre-set pressure. This supplements the back pressure control at surface should additional pressure be needed after closing the choke or if pressure diminishes during long static periods. Prior to the NBU design, the only effective solution was an Auxiliary Pump setup. This solution doubles the choke manifold footprint, relies on mechanical maintenance, and requires additional dedicated personnel at times. Most critically, the Auxiliary Pump lags the operation minutes before each use and is therefore functioned before static conditions when possible. However, unplanned and sudden events are commonplace – such as Rig Pump failures. When drilling formations with narrow pressure margins, unsafe gases, or crucial hole instability pressure limits, a few minutes can result in considerable and costly outcomes. Once installed during initial rig-up, the NBU is capable of injecting nitrogen-sourced back pressure instantaneously at the literal click of a button – avoiding costly and sometimes hazardous conditions. The NBU modernizes MPD operations and renders the Auxiliary Pump setup outdated in many applications. This paper details this innovative implementation of maintaining wellbore pressure, highlights several field examples of the NBU maintaining back pressure at critical times and shows how the layout used minimizes the operational footprint.

scholarly journals Experimental investigation on barite sag under flowing condition and drill pipe rotation

2020 ◽  
Vol 10 (8) ◽  
pp. 3497-3503
Author(s):  
Saeed Zaker ◽  
Pegah Sarafzadeh ◽  
Amin Ahmadi ◽  
Seyyed Hamid Esmaeili-Faraj ◽  
Roohollah Parvizi
Keyword(s):  
Flow Rate ◽  
Solid Phase ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Density Fluctuations ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Flow Loop ◽  
Well Control ◽  
Mud Loss

Abstract Using drilling fluids with optimum density is one of the most important approaches to stabilize the pressure of the bottom formation and prevent blowout through the drilling process. One of the common methods for this purpose is adding some additives with high specific gravity to the drilling fluid to tune its density. Among the possible chemicals, barite and hematite with the density of 4.2 and 5.2 g/cc are the most common additives. Unfortunately, although the application of these additives is advantageous, they have some drawbacks which the most important one is separation and settlement of solid phase called barite sag. The barite sag comes from barite, or other dense materials particles deposition resulted in undesired density fluctuations in drilling fluid can lead to mud loss, well control problems, poorly cementing and even pipe sticking which occurs in severe cases. With respect to these concerns, the current investigation is concentrated to obtain the relation between the dynamic conditions such as flow rate (0.308 and 0.19 l/s) and deviation angles of 30°,45°,60° and 90° and barite sag phenomenon through a flow loop equipment. Besides, the effect of drilling string rotational speed (70 rpm) on the barite deposition is investigated. The results not only indicate that increasing the flow rate from 0.19 l/s to 0.308 l/s can reduce the deposition rate, but also increasing the deviation angle from 45 to 60 o enhance the barite deposition to its maximum value. Graphic abstract

Analysis of Riser Gas Pressure from Full-Scale Gas-in-Riser Experiments with Instrumentation

2021 ◽  
Author(s):  
Mahendra R Kunju ◽  
Mauricio A Almeida
Keyword(s):  
Full Scale ◽  
Drilling Process ◽  
Control Methods ◽  
State University ◽  
Gas Migration ◽  
Well Control ◽  
Louisiana State University ◽  
Managed Pressure Drilling ◽  
Upward Transport ◽  
Minimal Fluid

Abstract As the use of adaptive drilling process like Managed Pressure Drilling (MPD) facilitates drilling of otherwise non-drillable wells with faster corrective action, the drilling industry should review some of the misconceptions to produce more efficient well control methods. This paper discusses results from full-scale experiments recently conducted in an extensively instrumented test well at Louisiana State University (LSU) and demonstrate that common expectations regarding the potential for high/damaging internal riser pressures resulting from upward transport or aggregation of riser gas are unfounded, particularly when compressibility of riser and its contents are considered. This research also demonstrates the minimal fluid bleed volumes required to reduce pressure build-up consequences of free gas migration in a fully closed riser.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

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

Eccentric String Reamer for ECD Reduction in the Depleted Field of Gulf of Thailand GoT

2021 ◽  
Author(s):  
Nichnita Tortrakul ◽  
Chatwit Pochan ◽  
Nardthida Kananithikorn ◽  
Thanapong Siripan ◽  
Basil Ching ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Low Cost ◽  
Operating Cost ◽  
Cost Effective ◽  
Operational Reliability ◽  
Drill String ◽  
Fluid Loss ◽  
Gulf Of Thailand ◽  
Drilling Depth ◽  
Annular Clearance

Abstract This paper presents a method of reducing equivalent circulating density (ECD) while drilling using eccentric string reamers (ESR) with adjustable gage stabilizer (AGS) in Gulf of Thailand (GoT). Reduced ECD in slimhole is desirable when drilling depleted reservoirs as reduced borehole pressure can reduce or delay drilling fluid loss events. Delaying losses can allow well depth to be increased with the prospect of penetrating otherwise unrealized pay horizons and increasing reserves capture. Several methods of reducing ECD were considered but most solutions included changing drill string and/or casing design specifications with prohibitive cost. A low-cost, low operational-impact solution was needed. Hole-opening is a method of increasing annular clearance, but well delivery requirements of ~4.5 days per well necessitates a one-trip solution without introducing significant ROP reduction or negatively impact bottomhole assembly (BHA) walking tendencies. Further, the preferred solution must be compatible with a high temperature reservoir drilling environment and must not undermine drilling system operational reliability. A simple but controversial tool for hole opening is ESR. ESR’s are simple in that there are no moving parts or cutter blocks to shift, and operating cost is low. They are controversial due to uncertainty that the tool eccentricity and drilling dynamics will successfully open hole to the desired diameter. Given that the intent of this hole-opening application is limited to creating annular clearance for fluid, not mechanical clearance, the eccentric reamer solution was chosen for field trial and potential development. A tool design challenge was to create a reamer geometry with the desired enlargement ratio (6⅛-in. to 6⅞-in.) while drilling, and reliably drift surface equipment and casing without complications. The ESR design must efficiently drill-out cement and float equipment as well as heterogeneous shale/sand/mudstone interbedded formation layers without significant vibration. If successful, the enlarged hole diameter will increase annular clearance, reduce ECD, improve hole cleaning, and allow drilling depth to be increased to capture additional reserves The plug and play functionality of the ESR required no changes to the existing rig site procedures in handling and making up the tool. The ESR drifts the casing and drills cement and shoe track with normal parameters. The ESR is run with standard measurements-while-drilling (MWD)/logging-while-drilling (LWD) AGS BHA and is able to reduce ECD providing the opportunity to drill deeper and increase barrel of oil equivalent (BOE) per each wellbore. Performance analysis has shown no negative effect on drilling performance and BHA walking tendency. The novelty of this ESR application is its proven ability to assist in increasing reserves capture in highly depleted reservoirs. The ESR is performing very efficiently (high ROP) and reliability is outstanding. In this application, the ESR is a very cost-effective and viable solution for slimhole design.

Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity

2021 ◽  
Author(s):  
Thad Nosar ◽  
Pooya Khodaparast ◽  
Wei Zhang ◽  
Amin Mehrabian
Keyword(s):  
Power Law ◽  
Flow Rate ◽  
Annular Flow ◽  
Rotation Speed ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Flow Loop ◽  
Annular Flows ◽  
Fluid Rheology ◽  
Pipe Rotation

Abstract Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity. Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows. The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.

Flow Loop Investigation of Lubricant Concentration Effect on Mechanical Friction in Drilling Fluids

2016 ◽  
Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Knud Richard Gyland ◽  
Bjørnar Lund ◽  
Sneha Sayindla ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
North Sea ◽  
Test Section ◽  
Drilling Fluid ◽  
Drill String ◽  
Drilling Fluids ◽  
Flow Loop ◽  
Steel Tubing ◽  
Steel Sections ◽  
Concrete Elements

A laboratory scale flow loop for drilling applications has been used for evaluating the effect of lubricants on skin friction during drilling and completion with oil based or low solids oil based fluids. The flow loop included a 10 meter long test section with 2″ OD free whirling rotating drill string inside a 4″ ID wellbore made of concrete elements positioned inside a steel tubing. A transparent part of the housing was located in the middle of the test section, separating two steel sections of equal length. The entire test section was mounted on a steel frame which can be tilted from horizontal to 30° inclination. The drilling fluids and additives in these experiments were similar to those used in specific fields in NCS. Friction coefficient was calculated from the measured torque for different flow velocities and rotational velocities and the force perpendicular to the surface caused by the buoyed weight of the string. The main objective of the article has been to quantify the effect on mechanical friction when applying different concentrations of an oil-based lubricant into an ordinary oil based drilling fluid and a low solids oil based drilling fluid used in a North Sea drilling and completion operation.

scholarly journals Analysis on the lateral vibration of drill string by mass effect of drilling fluid

2019 ◽  
Vol 10 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Chunxu Yang ◽  
Ruihe Wang ◽  
Laiju Han ◽  
Qilong Xue
Keyword(s):  
Drilling Fluid ◽  
Dynamic Pressure ◽  
Mass Effect ◽  
Drill String ◽  
Natural Vibration Frequency ◽  
Lateral Vibration ◽  
Test Results ◽  
Additional Mass ◽  
Mass Coefficient ◽  
Fluid Environment

Abstract. It is well known that the influence of the internal and external drilling fluid on the lateral vibration characteristics of drillstring cannot be ignored. In this paper, experiment apparatus for simulating drillstring vibration was established. Hammering method is used to measure drillstring lateral natural vibration frequency when the internal and external drilling fluid is considered. The test results show that the drilling fluid can decrease the natural frequency of the drillstring. Based on the simulation model, considering the influence of the internal and external drilling fluid, an external drilling fluid additional mass coefficient is derived considering the dynamic pressure effect caused by external drilling fluid. Additional mass coefficient can get the result with high precision, which can meet the needs of the project. the simulation results are in good agreement with the test results, and the error is within 2 %. This work provides a useful attempt and lays the foundation for the dynamics of the drill string in the drilling fluid environment.

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