A Three-Segment Hydraulic Model for Cuttings Transport in Coiled Tubing Horizontal and Deviated Drilling

2002 ◽  
Vol 41 (06) ◽  
Author(s):  
H. Cho ◽  
S.N. Shah ◽  
S.O. Osisanya
Keyword(s):  
Hydraulic Model ◽  
Cuttings Transport ◽  
Coiled Tubing

Coiled tubing drilling for unconventional reservoirs: the importance of cuttings transport in directional drilling

2014 ◽  
Vol 54 (1) ◽  
pp. 329
Author(s):  
Mohammadreza Kamyab ◽  
Nelson Chin ◽  
Vamegh Rasouli ◽  
Soren Soe ◽  
Swapan Mandal
Keyword(s):  
Rheological Properties ◽  
Oil And Gas ◽  
Fluid Velocity ◽  
Oil And Gas Industry ◽  
Unconventional Reservoirs ◽  
Directional Drilling ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Cleaning Efficiency ◽  
Coiled Tubing

Coiled tubing (CT) technology has long been used in the oil and gas industry for workover and stimulation applications; however, the application of this technology for drilling operations has also been used more recently. Faster tripping, less operational time, continuous and safer operation, and the requirement for fewer crew members are some of the advantages that make CT a good technique for drilling specially deviated wells, in particular, in unconventional reservoirs for the purpose of improved recovery. Cuttings transport in deviated and horizontal wells is one of the challenges in directional drilling as it is influenced by different parameters including fluid velocity, density and rheological properties, as well as hole deviation angle, annulus geometry and particle sizes. To understand the transportation of the cuttings in the annulus space, therefore, it is useful to perform physical simulations. In this study the effect of wellbore angle and fluid rheological properties were investigated physically using a flow loop that has been developed recently for this purpose. The minimum transportation velocity was measured at different angles and an analysis was performed to study the fluid carrying capacity and hole cleaning efficiency. The results indicated how the change in wellbore angle could change the cuttings transport efficiency.

Modeling of Cuttings Transport for Hole Cleaning in Horizontal and Highly Inclined Wells by Coiled Tubing Drilling

2003 ◽  
Author(s):  
Hiroshi Takahashi
Keyword(s):  
Flow Rate ◽  
Ground Surface ◽  
Critical Flow ◽  
Layer Model ◽  
Cuttings Transport ◽  
Critical Flow Rate ◽  
Hole Cleaning ◽  
Coiled Tubing ◽  
Two Layer Model ◽  
The Mathematical Model

The purpose of this study is to develop the mathematical model on the limit deposit velocity for hole cleaning in coiled tubing drilling. The model was developed for coarse cuttings by using the two-layer model. It was found from the calculated results by using the developed model that the minimum flow rate to convey the coarse cuttings, that is critical flow rate, increases with increasing ROP (rate of penetration) in the range of low ROP. However, the critical flow rate showed a maximum at certain ROP and then the critical flow rate decreases gradually with increasing ROP. Furthermore, it was confirmed that the effect of well inclination angle and cuttings diameter on the critical flow rate was significant. This result indicates that the behavior of cuttings in the well should be monitored carefully by measuring the supplied mud flow rate and cuttings delivered to the ground surface.

Multi-Trajectory Hydraulic Model for More Accurate Geosteering Constraints

2021 ◽  
Author(s):  
Sergey Alyaev ◽  
Benoit Daireaux
Keyword(s):  
Decision Support ◽  
Real Time ◽  
Target Selection ◽  
Initial Step ◽  
Hydraulic Model ◽  
Physical Models ◽  
Earth Model ◽  
Cuttings Transport ◽  
Planning Stage ◽  
Field Development

Abstract At the well-planning stage target selection usually accounts for drillability. However, during geosteering operations the drilling constraints are not updated and some fixed limits in terms of maximal inclination, dogleg severity, etc., are used instead. We demonstrate a methodology that uses fast physical models of the drilling hydraulics to calculate constraints and costs for geosteering dynamically during an operation. In field development, many companies have adopted workflows that use ensemble-based methods for decision support. A real-time variation of such a decision support system (DSS) has been recently proposed for geosteering. The DSS is capable of optimization full well trajectories across all realizations of the earth model and can consider multiple objectives and constraints simultaneously. We present a method that makes steady-state hydraulic computations for all possible trajectories ahead-of-bit simultaneously at a low added cost. The output of the computation can provide more precise constraints (geo-pressure margins and cuttings transport) and cost estimates for the DSS. In this paper we focus on verification and testing of the proposed multi-trajectory hydraulic model (MTHM). Discretization of the model acts as a trade-off between the preciseness of the computation and the computational speed. On our benchmark cases, a simulation that computes the hydraulic parameters for all trajectories with acceptable errors is fast enough for real-time geo-steering applications. Furthermore, we present a case based on data from the Norwegian Continental Shelf for which we demonstrate how hydraulic computations would influence the decisions of steering and stopping. Applying the DSS with the MTHM allows to precisely update the allowed steering interval, thus achieving safe operation while maximizing the expected well profit. We emphasize that integration of the drilling processes modelling as part of the decision support for the geosteering operation enables better decisions. This is facilitated by the digitalization of the oil industry, but still requires development of new approximate models of the drilling processes. This paper demonstrates the MTHM as an initial step towards integration of drilling and geosteering modelling.

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