Downhole CO2 partial pressure calculation and tubing material selection – a case study of an offshore oil field in the South China Sea

Purpose This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion design. CO2 partial pressure is the most important parameter to the oil and gas corrosion research for these wells which contain sweet gas of CO2. However, till now, there has not been a recognized method for calculating this important value. Especially in oil well, CO2 partial pressure calculation seems more complicated. Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. A case study was presented according to the new method, and two kinds of corrosion environment were determined. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. Based on the test results, 3Cr-L80 was recommended for downhole tubing. Combined with the field application practice, 3Cr-L80 was proved as a safety and economy anti-corrosion tubing material in this oil field. A proper corrosion parameter (mainly refers to CO2 partial pressure and temperature) can ensure a safety and economy downhole tubing anti-corrosion design. Design/methodology/approach Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. A field application practice was used. Findings It is necessary to calculate the CO2 partial pressure properly to ensure a safety and economy downhole tubing (or casing) anti-corrosion design. Originality/value The gas and oil separation theory and corrosion theory are combined together to give a useful method in downhole tubing anti-corrosion design method.

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Intensive Fracture Cluster Completion Strategy using Microemulsion Flowback Technology in a Daqing Tight Oil Field Application: Case Study (Russian)

10.2118/202062-ru ◽

2020 ◽

Author(s):

Xiaoling Yang ◽

Bilan Qiu ◽

Dunke Qi ◽

Deqing Lv ◽

Jian He ◽

...

Keyword(s):

Field Application ◽

Oil Field ◽

Tight Oil

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Compensation study of Boboroku, Jesse, Delta State, Nigeria

Property Management ◽

10.1108/pm-05-2016-0021 ◽

2017 ◽

Vol 35 (5) ◽

pp. 490-507 ◽

Cited By ~ 1

Author(s):

Christopher Oghenegweke Odudu ◽

Patience Osaiwie Iruobe

Keyword(s):

Market Value ◽

The Body ◽

Oil Well ◽

Case Study Methodology ◽

Content Type ◽

Market Values ◽

Full Compensation ◽

Compensation Claims ◽

Compulsory Purchase

Purpose The purpose of this paper is to examine issues of compulsory acquisition, evaluating the quantum of compensation paid to natives of communities whose farmlands are acquired and issues that must be dealt with to provide adequate compensation to claimants. Design/methodology/approach Using an oil well acquisition base in Boboroku, Jesse in Ethiope-West local government area of Delta State as a case study, various compensation claims were examined vis-à-vis market value claims in compulsory acquisition. Findings It was found that many claimants received N1,000.00 (naira) or less as full compensation claims for their crops while families lucky to own lands received more reasonable payments. It was also found that 40 of the 142 claimants in Boboroku community received only N4,146,120.00 as opposed to N8,802,750.00 they should have received under market values. Similarly, 39 claimants in Okuno should have received a market value of N3,195,920.00 as against N1,370,609.00 that was actually paid by the acquiring authority confirming that the rates applied were grossly inadequate. Practical implications It was established that there was no statutory provision for disturbance losses from revocation of land interests. Also, the productivity of economic crops and trees was not considered nor was the computation of claims based on market values. The paper further established that claims should be compensated on the basis of productivity value and life span of interests being acquired and not on arbitrary rates supplied by the acquiring authorities. Originality/value The case study methodology used in this paper enabled contribution to the body of studies which hitherto highlighted the issues of compulsory acquisition and quantum of compensation. It, therefore, adds to the problem-solving framework on compulsory purchase matters in Nigeria.

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A Fast Method of Selecting Offshore Oil Well Candidates for Multi Zone Cased Hole Frac Pack or Open Hole Completions for CNPC-Dagang Zhaodong Mature Oilfield: Case Study

10.2118/207023-ms ◽

2021 ◽

Author(s):

Heqiang Wang ◽

Chengliang Chi ◽

Ziyu Wang ◽

Shubo Zhou ◽

Xifeng Ma ◽

...

Keyword(s):

Production Rate ◽

Selection Process ◽

Field Application ◽

Oil Well ◽

Fast Method ◽

Daily Production ◽

Open Hole ◽

Key Steps ◽

Offshore Oil

Abstract To remain economical, mature offshore oil fields require unique, time-efficient and cost-efficient drilling and completion operations for each well. This paper is a case study of a rapid selection method for determining the operational process for each offshore oil well candidate and its application in the Zhaodong oilfield. In mature oilfields, maintaining production requires drilling and completing sidetrack wells. There are 3 key steps to rapidly selecting the most suitable drilling, completion and operational strategy for each well. First, review historical production data and operational costs to set production targets for each well. Second, evaluate the potential drilling and completion operations both technically and economically to achieve the target. Third, optimize the selected operations based on prior field application and production results. This process was applied with newly sidetracked wells in the Zhaodong oilfield. The wells were either completed using a multi-zone cased hole fracturing technique or an open hole completion technique, per the selection process. One candidate well completed with the multi-zone fracturing technique had a daily production rate of 134 tons of oil, and another candidate well completed with an open hole technique had a production rate of 236 tons of oil. These two wells were the most prolific in the Zhaodong oilfield. Using relatively basic engineering work integrated with simple economic calculations, this methodology is far less complicated and costly than computer simulation modeling for the operator. The performance in the Zhaodong oilfield reinforces this methodology used for selecting the proper candidate and completion process, providing more value and confidence for offshore operators.

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Experimental Study on the Corrosion Behavior of Produced Fluid on J55 Steel during CO2 Flooding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.773.179 ◽

2018 ◽

Vol 773 ◽

pp. 179-183

Author(s):

Jin Sheng Zhao ◽

Ying Jun Ju ◽

Mei Rong Tang ◽

Rong Huan Chen

Keyword(s):

Partial Pressure ◽

Corrosion Behavior ◽

Simulation Experiment ◽

Film Surface ◽

Oil Field ◽

Oil Well ◽

Field Development ◽

Oil Field Development ◽

Product Film ◽

Corrosion Simulation

CO2 flooding has been widely used in oil field development, but the produced fluid is easy to cause corrosion of tubing and casing. In order to determine the corrosion behavior of produced fluid on J55 steel during CO2 flooding, we use the simulated oil well produced fluid as corrosive medium and conduct the corrosion simulation experiment at high temperature and high pressure. The experimental results showed that the crystalline grain size of corrosion film surface is different for the different CO2 partial pressure. When CO2 partial pressure is greater than the critical pressure, the crystalline grain is not oblique six-party crystal structure, and the grains become small and compact, so the corrosion product film should have a good corrosion inhibition. Both static and dynamic corrosion of samples are serious. The research has a theoretical guiding significance on corrosion protection during CO2 flooding.

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