Modeling and Optimizing Rate of Penetration Using Intelligent Systems in an Iranian Southern Oil Field (Ahwaz Oil Field)

Abstract

For drilling optimization, an equation for the rate of penetration (ROP) is necessary. The rate of penetration depends on many factors such as formation properties, mud properties, weight on the bit, rotary speed, mud hydraulics, and size/type of bit. Due to the difficulty of mathematical modeling of ROP, researchers have used experimental results or field data to develop a correlation for ROP. In this study, a new model based on artificial neural networks (ANNs) is designed that is able to predict the ROP using real field data gathered in an Iranian oilfield (Ahwaz oilfield). The new model was successful in predicting ROP. To obtain operating parameters that lead to maximum ROP, the corresponding mathematical equation of an ANN model was implemented in a procedure using a genetic algorithm, which is one of the most reliable methods of optimization, and at different depths the parameters leading to maximum ROP were obtained. This model and its results can be used in Pabdeh and Gurpi formations in all Iranian oilfields and similar shaly formations in the Middle East such as the Iraq, Jaddia, and Aaliji formations corresponding to the Pabdeh formation and the Shiranish formation corresponding to Gurpi.     

提高小井眼钻井速度研究

小井眼与常规井眼的钻井工艺有较大差异,提高小井眼钻井速度有很大的实际意义。通过对小尺寸动力钻具局限性的研究,对小井眼钻具组合进行了优选,并且考虑小井眼的工作特点,为了使小井眼钻井钻头在井底达到最佳工作状态,通过理论计算,确定最优钻井参数,以达到机械钻速最佳。     

冲旋钻井机械钻速仿真研究

结合三牙轮钻头有关的理论,建立了冲旋钻井钻头的真实数学模型、真实井底模型和钻头牙齿与井底岩石互作用模型,用计算机仿真方法预测出了冲旋钻井机械钻速.应用结果表明,该模型可靠,计算结果与实际机械钻速基本一致,这些仿真模型可用于冲旋钻头优化设计和钻井参数的优选.     

靖南G68-16井小井眼钻井技术

G68-16井是靖南气田区块第1口φ206.4 mm小井眼试验井。针对该区块地层复杂地质特征,结合G68-16井小井眼钻井特点,优化钻具组合、优选钻头和螺杆型号,通过参数优化、钻井液性能维护以及预防井下复杂和事故等技术对策,使该井二开钻进4趟钻、划眼4趟钻完钻,钻井后期因处理井下复杂划眼历时16 d,完井作业顺利,平均机械钻速比原φ215.9 mm井眼提高了19%。试验取得较好的效果,为该区块进一步进行小井眼钻井试验积累了经验,为提速提供了有利的技术参考。     

提高深井钻井速度的几种技术

综述了国外近期深井钻井实践，探讨了深井钻井中深井钻井模拟技术、优化设计技术、近平衡钻井技术、钻头选型技术，应用井下动力钻具提高钻速技术，使用顶部驱动系统和随钻测量系统技术，深井钻井液技术和建立钻井分析及指挥中心等可行性技术，同时指出了我国深井钻井技术应开展的主要工作。     

哈拉哈塘地区钻井难点分析与提速关键技术

哈拉哈塘区块是中国石油塔里木油田黑油增储上产的主要区块之一,该区油藏埋深通常在6 800 m左右,钻井过程中存在中上部地层阻卡严重,容易泥包钻头,二叠系、石炭系井壁稳定性差,易垮塌,深部地层可钻性差,机械钻速低,超长裸眼事故复杂多和目的层含硫化氢、又漏又溢等技术难点。储层超深、地层复杂、钻井难度大、钻井周期长,严重制约了油田增储上产的步伐。针对这些施工难点,进行了优化钻井水力参数、优选钻头和涡轮、旋冲工具复合钻井、事故复杂预防、超长裸眼井壁稳定、碳酸盐岩储层安全钻井技术等研究应用,取得了明显成效,平均单井钻井周期较之前缩短1个月以上,有效控制了事故复杂的发生,实现了该区安全快速钻井的目标,解决了该区钻井速度慢、事故复杂多的技术难题。     

基于NSGA2的钻进参数多目标优化

在钻进参数优化过程中,机械钻速、钻头寿命和钻头比能是衡量钻井整体技术的重要依据。针对以单位进尺成本为目标的钻进参数优化问题,提出了钻进参数多目标优化方法,建立了以机械钻速、钻头寿命和钻头比能为组合的钻进参数多目标优化模型,并采用NSGA2多目标优化算法对模型进行仿真计算。仿真结果表明,采用NSGA2求解优化问题,能以较快的收敛速度在解空间内得出分布均匀的pareto最优解集,为决策者在工程实际中选择优化方案提供有效方法,大大提高了工作效率,同时也为优化钻井提供了一种新方法。     

深井钻井参数多目标可靠性优化

在多元随机钻井模式理论的基础上，提出了深井钻井参数多目标可靠性优化方法。松辽盆地北部地区深井钻井实践表明，利用可靠性优化方法可使机械钻速提高１倍左右。通过与实钻值对比分析，预测的钻头进尺、机械钻速和钻头寿命可靠度均在９５％以上，其中机械钻速平均相对误差为４．８％。     

钻井水力参数优化方法及应用现状

钻井水力参数优化设计对于提高钻井速度有着非常重要的意义。总结了目前在钻井优化软件中常用的3种水力参数优化设计原则及其在钻井工程中的应用方法,并介绍了这些优化方法的差异和发展趋势。针对国外主要钻头生产商提供的水力计算软件及部分钻井仿真软件中的水力学计算模块进行了对比分析,指出了发展具有自主知识产权的钻井水力优化设计软件需要注意的问题及解决方法,对于优化钻井设计具有指导意义。     

东营凹陷中央隆起带北部深层钻井技术难点与对策

东营凹陷中央隆起带北部深层钻井存在地层倾角大、地层岩石可钻性差、钻头选型困难、盐膏层发育、地层压力系统复杂、地层温度高等技术难点,导致机械钻速低、钻井周期长。为此,胜利油田提出了以下技术对策:开展地层岩石可钻性研究,优选钻头;利用“PDC钻头＋螺杆钻具”进行复合钻进;进行旋冲钻井技术、井底涡轮增压钻具配合超高压射流钻头钻井试验;推广应用气体钻井技术;优选钻井液体系。现场应用和试验结果表明,所提出的技术对策可行、有效,并在应用和试验过程中形成了东营北带深部地层钻井提速配套技术。      

优快钻井技术在安棚高含碱油田的应用

安棚高含碱油田地质构造和油气藏类型复杂、岩石可钻性差以及高含碱地层对钻井液和水泥浆的影响严重,致使该地区钻井速度低、井下复杂情况多以及井身质量和固井质量差,为此开展了综合配套技术研究,形成了地层自然造斜规律应用、地层可钻性评价与钻头优选、钻井参数和水力参数优选、抗碱钻井液体系研究及抗碱固井技术研究等5项配套技术。经现场应用表明,综合配套技术可提高机械钻速70.98%,缩短建井周期65.21%,井下复杂及事故时效减少78.80%,固井质量合格率提高124.47%,取得了较好的经济效益。     

Hydraulic Pulsed Cavitating Jet-Assisted Drilling

Abstract

How to improve drilling rate in deep wells has been a hot subject. Based on modulating pulse jet and cavitating jet, a new drilling tool is designed which couples advantages of both pulse jet and cavitating jet. When drilling fluid flows through the tool during the drilling process, fluid is modulated to pulse and cavitate. Thus, pulse cavitating jet is formed at the outlet of the bit nozzle. Because of jet pulsation, cavitating erosion and local negative pressure affect bottomhole rock. Cleaning and breaking is enhanced and penetration speed is improved. Oil field tests in five wells show good applicability of the tool to bit types, formation, drilling densities, flow rates, and dynamic hydraulic drilling motors, etc. As a result, penetration rates are improved ranging from 10.1 to 31.5%; the maximum working time is about 235.5 hr in downhole. Pulse and cavitating jet coupling will afford an effective means to improve drilling rate for deep wells.     

钻井参数优选新方法

目前常用的钻速模式把地层因素的影响作为一个“口袋”系数．因此这些方程的应用只能局限于邻井或同一地区相似的地质备件，缺乏通用性，给钻井参数的定量优选带来很大困难。而岩石可钻性是表征岩石破碎难易程度的一个力学参数，是地层因素的综合体现，是影响钻速的最重要因素。以大庆油田部分区块地质夸件及大量室内试验为基础，建立了基于岩石可钻性表示的钻速模式和钻井参数优选的目标函数，应用实例表明，该模式参数获取方便，通用性强，为实现特定区域油田钻井参数的优选提供了一种新方法。     

流花油田地层岩石力学参数评价及钻头选型技术

钻头的合理选型对提高钻进速度、降低钻井成本起着重要作用。应用改进的经济效益指数法对流花LH11-1区块的钻头使用效果进行了评价,结合地层岩石力学参数评价结果优选出了与流花LH11-1区块地层相适应的钻头型号。改进的经济效益指数法考虑了钻头磨损的影响,从而使评价结果更加客观合理。由于没有搜集到按垂深进行地层划分的数据,提出了按照地层岩石力学性质进行地层分层的新方法,该地层分层方法首先将地层的多种岩石力学性质进行聚类分析,然后根据层内离差平方和最小,层间离差平方和最大的原理进行地层划分,此种地层划分方法对于钻头优选、钻进参数优化以及合理制定钻进措施等具有重要意义。现场应用结果表明,文中给出的钻头选型结果和地层分层方法是合理的,能够在大位移井中应用。     

三牙轮钻头数字化钻进仿真评价系统开发及应用

钻头数字化钻进仿真是一种将钻头-岩石互作用仿真理论与钻头性能评价及结构优化相结合的实用化技术,开发钻头钻进仿真软件的主要目的是为钻头设计及性能分析提供技术手段。在已完成的三牙轮钻头仿真模型研究基础上,重点解决了数据输入、模型数值算法实现、仿真结果可视化等问题,利用MATLAB完成了软件开发。开发的软件能够模拟钻头几何结构,分析理想状态下钻齿的运动特性,模拟钻头在直井、水平井和定向井不同工况下的钻进过程,并对钻头破岩过程中的相关物理参数进行分析评价。利用该软件对某型号三牙轮钻头进行了台架试验及布齿结构参数优化设计,仿真结果具有直观及定量化的特点,表明利用该软件对钻头进行优化设计方便、快捷且可靠性高。      

鄂北优快钻井技术研究与应用

对鄂尔多斯盆地北部区块地层的特点和主要钻井难点进行了分析，从优选钻头类型、优化钻井参数、钻井液维护和处理、制订防止钻具失效措施等方面给出了优快钻井技术方案。现场应用表明，鄂尔多斯盆地北部区块实施该技术方案后，大幅提高了钻井速度，缩短了钻井周期，降低了钻井成本，值得在该区块进一步推广应用。     

A New Method for Determining Bourgoyne and Young Penetration Rate Model Constants

Abstract

The objective of any drilling operation is to drill a well with the least possible cost and in the shortest time in compliance with safe operation. This objective is usually achieved by applying the drilling parameters in such a way that the fastest drilling rate would result. Several drilling penetration rate models have been proposed for estimation of penetration rate based on different drilling parameters. One of the most frequently used models for estimation of drilling penetration rate is the Bourgoyne and Young model. This model relates the penetration rate to several drilling parameters. There are eight unknown constants in this model. Bourgoyne and Young have proposed multiple regression analysis for obtaining these constants. Because the constant values obtained by multiple regression analysis are sometimes meaningless and are not in the recommended ranges, other methods for determining these coefficients are suggested. Some authors have used least squares data fitting methods and trust region approaches to obtain these coefficients. In this article, a new method is used for this purpose. A set of possible answers is chosen from the recommended bounds. Then the best fitted answers are selected and compared with a new set of possible answers. This trial is repeated until the desired answers are obtained. The results show the proficiency of the new methodology to determine constant coefficients of the Bourgoyne and Young penetration rate model.     

人工神经网络在大庆深井钻头优选中的应用

针对大庆地区深井地层硬、温度高、倾角大等特点,将对深井钻速影响较大的12个因素作为输入层神经元,建立了人工神经网络优选钻头方法。该方法将钻头优选的定量方法和定性方法相结合,使钻头优选结果更加可靠。针对侏罗系地层高硬度、强研磨性等特点,研究并试验了几种特殊类型的钻头。根据对新型钻头钻井结果及以往大庆深井钻井所用钻头数据的统计分析,建立了大庆地区钻头应用情况数据库。在此基础上,应用人工神经网络法对大庆油田深井使用的钻头进行了优选,在大庆2口深井进行的现场试验表明,钻井速度提高了20%以上。     

PDC钻头钻进影响因素分析

运用多元分析的方法,结合实钻资料对PDC钻头钻进过程进行了全面系统的分析,得到多因素相互作用下各因素对钻进过程的影响程度,对于指导现场施工具有一定价值。     

New development of theories in gas drilling

Theories established from engineering fundamentals have been of great value in supporting the design and execution of drilling operations in gas drilling where gas is used as a drilling fluid.This work presents an overview of new theories developed in recent years for special gas drilling operations including horizontal wells.These new theories are found in the areas of gas-mixture flow hydraulics in deviated and horizontal boreholes,hole cleaning of solids accumulation,hole cleaning of formation water,flow diverging for washout control,bit orifice optimization,and depression of formation water influx.This paper provides drilling engineers with updated mathematical models and methods for optimizing design to improve gas drilling performance.