Riser Tensioner Force Variations

1978 ◽  
Vol 18 (06) ◽  
pp. 399-408
Author(s):  
T.J. Kozik ◽  
J. Noerager
Keyword(s):  
Support System ◽  
Strong Dependence ◽  
Technical Conference ◽  
Ball Joint ◽  
Joint Force ◽  
Support Mechanism ◽  
Original Manuscript ◽  
Drilling Operations ◽  
Force Variation ◽  
Tank Pressure

Original manuscript received in Society of Petroleum Engineers office Feb. 24, 1976. Paper accepted for publication June 14, 1977. Revised manuscript received Aug. 21, 1978. Paper (SPE 6309, OTC 2648) first presented at the Eighth Annual Offshore Technical Conference, held in presented at the Eighth Annual Offshore Technical Conference, held in Houston, May 3-6, 1976. Abstract Excessive riser-force variation on the upper joint in a riser string can lead to buckling and excessive fatigue. This variation is caused by two components of the riser support system - the riser tensioning system and the telescopic, or slip, joint. Using specific examples, two conclusions are reached. First, the force variation at the top of the riser string may be much greater than that indicated by monitoring the tensioner system's air-tank pressure. Second, a major contribution to this pressure. Second, a major contribution to this variation can be pressure drop in the air valves. Introduction The riser tensioners and slip joint (Fig. 1) form the support system for the riser string used in floating drilling operations. Although tensioners are the primary support mechanism, their forces are transmitted through the slip joint to the upper joint in the riser string. In many deep-water drilling operations, the riser string is isolated in bending by an upper ball joint from the more massive telescopic joint. This upper ball joint interacts directly with the riser string; therefore, the forces seen at that joint become riser-string forces because of the tensioner support system. Ideally, the tensioner support-system forces at the upper ball joint should provide a net axial load on the riser string and should be constant in magnitude as well as direction. However, the nonideal behavior of the riser tensioners - as well as the inertia and geometrical effects associated with vessel, slip joint, and riser-string motions - result in load variations. Generally, the upper ball-joint force vector depends on time. No limits as yet have been determined for allowable variations of the riser-string forces resulting from the riser support mechanism. Nevertheless, measuring these variations analytically and qualitatively is important when assessing the effectiveness of the support mechanism or when providing important information about the boundary providing important information about the boundary conditions necessary to analyze the riser string. Our paper has two purposes. First, to emphasize by numerical examples the strong dependence of riser-tensioner force variations on the character of the assumed losses (pressure chop) in the tensioner-system air valves. Second, to present an analytical expression and numerical results for the tensioner-system force variations at the upper ball joint, thereby emphasizing the strong effects of vessel motion on riser-string force. TENSIONER ANALYSIS The typical drilling riser tensioner is a hydropneumatic mechanical system (Fig. 2) that provides tension in the cable attached to and supporting the outer barrel of the slip joint. Kozik studied the cable tensioner variation (r) resulting from cable motion. A convenient form for his equation is .....................(1) SPEJ P. 399

Development of a Commercial Wireline Retrievable Coring System

1998 ◽  
Vol 1 (06) ◽  
pp. 489-495 ◽  
Author(s):  
Tommy Warren ◽  
Jim Powers ◽  
David Bode ◽  
Eric Carre ◽  
Lee Smith
Keyword(s):  
Economic Evaluation ◽  
Coalbed Methane ◽  
Technical Conference ◽  
The Core ◽  
Core Recovery ◽  
Drilling Equipment ◽  
Original Manuscript ◽  
The Impact ◽  
Conventional Drilling ◽  
Target Depth

This paper (SPE 52993) was revised for publication from paper SPE 36536, first presented at the 1996 SPE Annual Technical Conference and Exhibition, Denver, 6-9 October. Original manuscript received for review 11 October 1996. Revised manuscript received 22 September 1998. Paper peer approved 23 September 1998. Summary A Wireline retrievable coring system for use with conventional drilling equipment is described. The coring system was developed and tested for application in evaluating coalbed methane prospects where a large quantity of core is required, and it is essential that the core is processed soon after it is cut. A drill plug allows for alternation between coring and drilling without tripping the drillstring. The system is particularly advantageous for coring long intervals, multiple zones relatively close together, or when the exact target depth is unknown. The system has been used to core more than 4940 m (15,057 ft) in Poland, Germany, and France, with a combined core recovery of 94%. In addition, the impact of varying rig costs on total savings is factored into the overall economic evaluation of the system. P. 489

Upper Ball Joint Force Variations due to Riser Tensioner and Vessel Motions—Part II: Analysis and Computer Simulation

1990 ◽  
Vol 112 (3) ◽  
pp. 200-207 ◽  
Author(s):  
T. J. Kozik ◽  
J. E. Lowell ◽  
A. Ertas
Keyword(s):  
Computer Simulation ◽  
General Equation ◽  
Ship Motion ◽  
Joint Motion ◽  
Ball Joint ◽  
Joint Force ◽  
Field Operation ◽  
Breakaway Torque ◽  
Cable Forces

An analysis of the variation of forces acting on the upper ball joint of a riser string due to the drill ship motion and riser tensioner dynamic has been conducted. The analysis includes the effect of breakaway torque on the tensioner sheaves while assuming vessel and upper ball joint motion to be independent. General equation for the tensioner cable forces and for the forces exerted on the riser upper ball joint by the ship joint-tensioner system derived in Part I are solved. The variation in the tensioner cable forces is compared to data generated in field operation.

Pressure-Volume-Temperature Correlations for Gulf of Mexico Crude Oils

1998 ◽  
Vol 1 (05) ◽  
pp. 416-420 ◽  
Author(s):  
G.E. Petrosky ◽  
F. Farshad
Keyword(s):  
Technical Conference ◽  
Pressure Solution ◽  
Gas Oil ◽  
Pvt Properties ◽  
Volume Factor ◽  
Original Manuscript ◽  
Oil Formation Volume Factor ◽  
Solution Gas ◽  
Oil Formation ◽  
Temperature Correlations

This paper (SPE 51395) was revised for publication from paper SPE 26644, first presented at the 1993 SPE Annual Technical Conference and Exhibition, Houston, 3-6 October. Original manuscript received for review 25 October 1993. Revised manuscript received 1 October 1997. Paper peer approved 28 January 1998. Summary New empirical pressure-volume-temperature (PVT) correlations for estimating bubblepoint pressure, solution gas-oil ratio (GOR), bubblepoint oil formation volume factor (FVF), and undersaturated isothermal oil compressibility have been developed as a function of commonly available field data. Results show that these PVT properties can be predicted with average absolute errors ranging from 0.64% for bubblepoint oil FVF to 6.66% for undersaturated isothermal oil compressibility. P. 416

A Multi-Agent System Approach to Mobile Negotiation Support Mechanism by Integrating Case-Based Reasoning and Fuzzy Cognitive Map

2011 ◽  
pp. 218-238
Author(s):  
Kun Chang Lee ◽  
Lee Namho
Keyword(s):  
Support System ◽  
Cognitive Map ◽  
Fuzzy Cognitive Map ◽  
Case Based Reasoning ◽  
Negotiation Support ◽  
Support Mechanism ◽  
Multi Agent ◽  
Effective Decision Support ◽  
Primary Advantage ◽  
Case Based

This paper proposes a new type of multi-agent mobile negotiation support system named MAM-NSS in which both buyers and sellers are seeking for best deal given limited resources. Mobile commerce or m-commerce is now on the verge of explosion in many countries, triggering the need to develop more effective decision support system capable of suggesting timely and relevant action strategies for both buyers and sellers. To fulfill research purpose like this, two AI methods such as CBR (case-based reasoning) and FCM (fuzzy cognitive map) are integrated, and named MAM-NSS. Primary advantage of the proposed approach is that those decision makers involved in m-commerce regardless of buyers and sellers can benefit from the negotiation support functions that are derived from referring to past instances via CBR and investigating interrelated factors simultaneously through FCM. To prove the validity of the proposed approach, a hypothetical m-commerce problem is developed in which theaters (sellers) seek to maximize profit by selling its vacant seats to potential customers (buyers) walking around within reasonable distance. For experimental design and implementation, a multi-agent environment Netlogo is adopted. Simulation reveals that the proposed MAM-NSS could produce more robust and promising results that fit the characteristics of m-commerce.

Interpretation of Well-Block Pressures in Numerical Reservoir Simulation(includes associated paper 6988 )

1978 ◽  
Vol 18 (03) ◽  
pp. 183-194 ◽  
Author(s):  
D.W. Peaceman
Keyword(s):  
Single Phase ◽  
Technical Conference ◽  
Two Dimensions ◽  
Significant Treatment ◽  
Hole Pressure ◽  
Numerical Reservoir Simulation ◽  
Drainage Radius ◽  
Bottom Hole ◽  
Original Manuscript ◽  
Grid Block

Original manuscript received in Society of Petroleum Engineers officeJune 16, 1977. Paper accepted for publication Dec. 20, 1977. Revisedmanuscript received April 3, 1978. Paper (SPE 6893) first presentedat the SPE-AIME 52nd Annual Fall Technical Conference and Exhibition, held in Denver, Oct. 9-12, 1977. Abstract Examination of grid pressures obtained in thenumerical simulation of single-phase flow into asingle well shows that the well-block pressure isessentially equal to the actual flowing pressure ata radius of 0.2 x. Using the equation forsteadystate radial flow then allows calculation ofthe flouring bottom-hole pressure. The relation between pressures measured in abuildup test and the simulator well-block pressureis derived. In particular, the buildup pressure andthe well-block pressure are shown equal at ashut-in time of 67.5 ct x2/k. This is aboutone-third the shut-in time stated by previous authors, who derived their results from an erroneousassumption concerning the significance of thewell-block pressure. When only a single buildup pressure is observedat a different shut-in time, an adjustment to theobserved pressure can be made for matching with the simulator well-block pressure. Introduction When modeling reservoir behavior by numericalmethods, inevitably the horizontal dimensions ofany grid block containing a well are much larger than the wellbore radius of that well. It long hasbeen recognized that the pressure calculated for awell block will be greatly different from the flowingbottom-hole pressure of the modeled well, but theliterature contains few specific guides as to how tomake the correction. In this study, we confine our attention tosinglephase flow in two dimensions. Consider the fiveblocks abstracted from a regular grid system(Fig.1) with the center block containing a well producingat rate q. Schwabe and Brand proposed therelationship 2 kh Pe - Pwfq = ------- -----------------,..............(1)1n(r /r) + se w where re is taken equal to x, and pe is an effectivepressure at the"drainage radius," re, obtainedfrom4Pe = Po + Fi (Pi - Po).i=1 Schwabe and Brand did not define Fi, but seemedto imply that it be taken as zero. Thus, in theabsence of a skin effect, Eq. 1 reduces to 2 kh Po - Pwfq = ------- -------------...................(2)1n (x/r) w The most significant treatment of this subjectuntil now was that of van Poollen et al. Theystated that the calculated pressure for a well block should be tithe areal average pressure in theportion of the reservoir represented by the block. SPEJ P. 183^

Horizontal Well IPR Calculations

1998 ◽  
Vol 1 (05) ◽  
pp. 392-399 ◽  
Author(s):  
L.K. Thomas ◽  
B.J. Todd ◽  
C.E. Evans ◽  
R.G. Pierson
Keyword(s):  
Horizontal Well ◽  
Numerical Solutions ◽  
Horizontal Wells ◽  
Technical Conference ◽  
Flow Coefficient ◽  
Darcy Flow ◽  
Analytical And Numerical Solutions ◽  
Original Manuscript

This paper (SPE 51396) was revised for publication from paper SPE 36753, first presented at the 1996 SPE Annual Technical Conference and Exhibition, Denver, Colorado, 6-9 October. Original manuscript received for review 24 October 1996. Revised manuscript received 23 October 1997. Paper peer approved 7 July 1998. Summary This paper presents the calculation of near-wellbore skin and non-Darcy flow coefficient for horizontal wells based on whether the well is drilled in an underbalanced or overbalanced condition, whether the well is completed openhole, with a slotted liner, or cased, and on the number of shots per foot and phasing for cased wells. The inclusion of mechanical skin and the non-Darcy flow coefficient in previously published horizontal well equations is presented and a comparison between these equations is given. In addition, both analytical and numerical solutions for horizontal wells with skin and non-Darcy flow are presented for comparison. P. 392

NMR as Standard Porosity Tool in the San Jorge Basin: Log Responses and Applications

1998 ◽  
Vol 1 (06) ◽  
pp. 504-508 ◽  
Author(s):  
Fernando Solanet ◽  
Alberto Khatchikian ◽  
Eduardo Breda
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Size Distribution ◽  
Pore Size ◽  
San Antonio ◽  
Technical Conference ◽  
Resonance Imaging ◽  
Imaging Tool ◽  
Original Manuscript

This paper (SPE 52939) was revised for publication from paper SPE 38735, first presented at the 1997 SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 5-8 October. Original manuscript received for review 7 October 1997. Revised manuscript received 17 August 1998. Paper peer approved 16 September 1998. Summary This paper describes our experience with nuclear magnetic resonance (NMR) logs since their introduction in the San Jorge basin in June 1995. To date, more than 400 logs have been run by Western Atlas and Schlumberger using Numar's magnetic resonance imaging tool (MRIL) and combinable magnetic resonance (CMR) tools, respectively, and more than 2,000 zones have been perforated and tested. This has allowed us to characterize the response of the tools in shaly and tuffaceous sands, compare the response of the Numar and Schlumberger tools with each other and with cores, detect the limitations of present tool designs, and relate NMR pore-size distribution and permeability to oil production. P. 504

Advances in Test Techniques Based on Multifunctional Sting Support System for 8m×6m Wind Tunnel

2013 ◽  
Vol 336-338 ◽  
pp. 880-884
Author(s):  
Li Tao Fan ◽  
Xue Feng Duan ◽  
Wei Xue
Keyword(s):  
Wind Tunnel ◽  
Support System ◽  
Vibration Suppression ◽  
Weight Bearing ◽  
Control Unit ◽  
Maximum Weight ◽  
Support Mechanism ◽  
Test Efficiency ◽  
Motor Control System ◽  
Suppression System

Multifunctional sting support system at high angle of attack is the main way of support for aircraft test in 8m×6m wind tunnel. In recent five years, a series of supporting facility has been developed to improve test efficiency and enhance the finer testing and measuring capability. New developed vibration suppression system can not only enlarge the maximum weight-bearing of the support mechanism, but also reduced the vibratory frequency of a model. Power (motor) control system was modified to adapt to the requirement of 0.2% precision. TG1801 balances were designed and manufactured with high precision and good stiffness. A remote control unit has been applied for a specific aircraft test as model facility to reduce labor intensity and raise test efficiency. Aircraft test efficiency in 8m×6m wind tunnel has been increased gradually and data accuracy reaches the advanced international level through these improvements.

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