scholarly journals Modeling research on the extreme hydraulic extension length of horizontal well: impact of formation properties, drilling bit and cutting parameters

2021 ◽  
Vol 11 (3) ◽  
pp. 1211-1222
Author(s):  
Nu Lu ◽  
Bo Zhang ◽  
Tao Wang ◽  
Qianming Fu
Keyword(s):  
Horizontal Well ◽  
Formation Pressure ◽  
Fracture Pressure ◽  
Bed Height ◽  
Pump Rate ◽  
Drilling String ◽  
Pump Pressure ◽  
Cutting Bed ◽  
Extension Length ◽  
Drilling Bit

AbstractHorizontal well can increase well productivity and improve the economic benefit, which significantly promotes the development of shale gas, tight oil and heavy oil. Moreover, it plays an important role in the development of natural gas hydrate. Horizontal extension ability is one of the key indexes of horizontal well, but it is always impacted by formation properties and well structure. Therefore, a model is established to analyze the impact of formation properties and well structure as comprehensive as possible, which considers not only traditional influencing factors, like formation pressure and drilling bit parameters, but also other key factors, including cutting particle size, wellbore diameter and cross section. Based on the analysis, some advises are proposed for field application. The analysis indicates that horizontal well has stronger extension ability in the formation with low formation pressure and high fracture pressure, but it is still limited by pump pressure. Under-balanced drilling can strength the extension ability in high formation pressure by reducing drilling mud density. The natural fractures in formation should be noted when drilling long horizontal well. The extension length increases and then decreases with the cutting particle size, so cutting particle has optimal size for the horizontal extension length, which can be adjusted by the rate of penetration and rotation speed. The extension length increases first and then decreases with the gap between drilling string and hole. Considering the demand of rock breaking and cutting sweeping around drilling bit, it is not recommended to adjust the drilling bit parameters. Both the cutting bed height and drilling string eccentricity have impact on horizontal extension length by changing minimum cutting-carry pump rate and annular pressure drop. Under different combinations of above two parameters, minimum cutting-carry pump rate and horizontal extension length are determined by different factors and can be divided into three parts, including acceptable cutting bed height, cutting lifting efficiency, pump pressure and total circulation pressure loss and well bottom pressure and formation fracture pressure. The findings of this study can help for better understanding of horizontal well hydraulic extension length and optimization method.

Evaluate Sensitivity and Feasibility of Influencing Factors to Increase the Extreme Hydraulic Extension Length of Horizontal Well

2017 ◽  
Author(s):  
Bo Zhang ◽  
Zhichuan Guan ◽  
Nu Lu ◽  
A. R. Hasan ◽  
Chuanbin Xu ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Horizontal Well ◽  
Extension Length

Experimental Device of Drilling String Dynamics in Horizontal Well and its Application

2013 ◽  
Vol 683 ◽  
pp. 690-693 ◽  
Author(s):  
Dong Dong Shao ◽  
Zhi Chuan Guan ◽  
Xin Wen
Keyword(s):  
Horizontal Well ◽  
Lateral Displacement ◽  
Lateral Force ◽  
Experimental Results ◽  
Experimental Device ◽  
Simulated Experiment ◽  
Bottom Hole ◽  
Drilling String ◽  
Rotary Speed ◽  
Set Up

According to the principle of similitude, a simulation experimental device for investigating drilling string dynamics in horizontal well was designed and set up. The rotary speed, WOB, drilling string lateral displacement, bottom hole WOB fluctuations and lateral force of the bit, etc. can be measured under different WOB and rotary speed by the experimental device; Some debugging experiments have been done by means of the device under different weights on bit and rotary speeds. The simulated experiment has many advantages comparing to the actual experiment, such as less operators, less times and moneys. It is easy to operate, the drilling string movement can be visually observed and all of the experimental results can be used to the actual drilling.

The Development and Field Applications of Ultra-Deepwater Structural Conductor Jetting in Western South China Sea

2021 ◽  
Author(s):  
Zhong Li
Keyword(s):  
South China Sea ◽  
South China ◽  
Technical Problems ◽  
China Sea ◽  
Size Selection ◽  
Fracture Pressure ◽  
Successful Case ◽  
Pump Rate ◽  
Western South China Sea ◽  
Weight On Bit

Abstract Lingshui X-1 block is located in ultra-deepwater region in western South China Sea. Drilling in this area are encountering many technical problems, such as low temperature, poor lithology in shallow formation, low fracture pressure gradient, gas hydrate and shallow geological hazards, which bring great technical challenges to subsea wellhead stability (Yang et al., 2013). In order to ensure wellhead stability and improve top-hole operation efficiency, jetting technology was used for spud-in. First of all, carrying capacity curve of structural conductor was obtained from mechanics analysis of shallow seabed soil in Lingshui X-1 block. Secondly, structural conductor size selection and load analysis were carried out to determine safe setting depth of structural conductor in Lingshui X-1 block. Finally, bit stick-out, bit size selection, Weight on Bit (WOB) and pump rate were optimized on the basis of comprehensive analysis of ultra-deepwater under top-hole jetting technology and BHA characteristics. Well LSX-1-1 was taken as an example to illustrate field operation for top-hole jetting. This successful case of top-hole jetting technology in Lingshui X-1 block of western South China Sea could provide technical guidance for future drilling activity in similar ultra-deepwater wells.

The Influence of Time and Pump Rate on Stress Interference in Zipper Fracturing

2014 ◽  
Vol 962-965 ◽  
pp. 512-516 ◽  
Author(s):  
Hai Tao Li ◽  
Da He ◽  
Tao Gao ◽  
Yong Quan Hu
Keyword(s):  
Horizontal Well ◽  
Fracture Network ◽  
Stress Change ◽  
Production Performance ◽  
Fracture Width ◽  
Stress Shadow ◽  
Pump Rate ◽  
Initial Fracture ◽  
High Production ◽  
Induced Fractures

Zipper fracturing is becoming popular as a method that may be used to improve production performance in wells in pad drilling. Fracture network is expected in zipper fracturing, which leads to high production. The time between two consecutive stages of a horizontal well, leak-off coefficient, and pump rate have a great effect on the induced fractures, which leading to a more efficient fracture network. We will focus on the factor of time and pump rate in this paper. For the same leak-off coefficient, firstly, different initial width is calculated in different pump rate, and then with change equation is formulated from Carter’s leak off model. The stress change of different initial fracture width can be illustrated according to this model. The results show that: the bigger pump rate, the bigger initial width, which leads to a slower stress change. There is an inspiration for field zipper fracturing. Longer time between consecutive stages, that mean decrease in stress shadow, is beneficial to complex networks.

Fracture Pressure Stimulation of Multi-Stage Horizontal well Fracturing with Several Perforating Clusters

2013 ◽  
Vol 785-786 ◽  
pp. 998-1004
Author(s):  
Song Wang ◽  
Xi Ran Guo ◽  
You Shi Jiang ◽  
Chang Yu Liu ◽  
Yong Ming Li ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Element Model ◽  
Simulation Method ◽  
Oil Field ◽  
Parameter Analysis ◽  
Gas Reservoirs ◽  
Fracture Pressure ◽  
Multi Stage ◽  
Fracturing Process ◽  
Treatment Data

Multi-stage horizontal well fracturing with several perforating clusters in each stage is an important completion technique in tight gas and shale gas reservoirs. Due to the stress field interference, different perforation parameters and unevenly distributed cluster distance lead to individual fracture pressure, which determines whether the clusters can all be initiated during the fracturing process. The ABAQUS software can be used to create the 3D finite element model of horizontal multi-stage fracturing with several clusters and to analyze the fracture pressure influenced by different parameter set of helix perforation, such as phase angle, tunnel diameter, tunnel depth and perforating density. Based on the results of perforation parameter analysis, the simulation method can be validated with actual treatment data from Jilin oil field.

scholarly journals Prediction of Formation Pressure Gradients of NC98 Field-Sirte Basin-Libya

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Ahmed Tunnish ◽  
Mohammed Nasr ◽  
Mahmoud Salem
Keyword(s):  
Pore Pressure ◽  
Well Logging ◽  
Pressure Gradients ◽  
Formation Pressure ◽  
Empirical Methods ◽  
Fracture Pressure ◽  
Significant Step ◽  
Sirte Basin ◽  
Formation Pore Pressure ◽  
Oil Company

The prediction of formation pore pressure and fracture pressure gradients is a significant step towards the drilling plan. In this study, the formation pressures of twelve wells from NC98 field-Sirte Basin (Waha Oil Company) were calculated by employing empirical methods, Eaton’s equations, that depend on the real drilling and well-logging data. Regarding the results, the normal pore pressure in the NC98 field in Sirte basin is 0.437 Psi/ft, and it is extending from the top of the wells in the investigated area to 7,000 ft. A subnormal to normal pore pressure zone is noticed in the interval of 7,000 ft. to 9,000 ft. Then, slightly subnormal to somewhat abnormal (overpressure) region is seen from 9,000 ft. to 11,200 ft. Beyond to that depth and down to the top of the reservoir, the overpressure zone was clearly observed. Based on the results, the casing setting depth and the equivalent mud weight were simply determined for the area of study.

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