Standards Development

Scope

This document proposes the principles, design, and requirements for mechanical water-control completion of oil wells, including selection of water-control completion method, parameter design, procurement, operation requirements and evaluation, etc

Purpose

At present, many oilfield development has entered a period of high water cut, including but not limited to oilfields in the Middle East, Africa, Americas, the North Sea and China.

The rapid growth water cut and high water production rate in oil wells make it difficult to stabilize production, and will seriously affecting the overall economics of the oilfield development. There is a strong need for water-control.

Mechanical water-control completion has gradually become an important measure, the total application worldwide has exceeded 3000 wells and keep growing. International mechanical water-control completion design is usually completed by suppliers, and carrying out water-control design for its own tools; CNOOC mechanical water-control completion design includes selection of ICD and AICD water-control methods based on adaptability and regularity of water-control methods in different reservoir conditions, which is determined by simulation of different types of water-control tools, and providing water-control tools performance requirements to suppliers.

CNOOC mechanical water-control completion design has been continuously applied offshore since 2008. According to the statistics of 121 wells in the South China Sea from 2008, the water-control effective rate has increased from the average of 77% before 2020 to 93% at present.

The only standard related to water-control is API Specification 19 ICD-2020, Inflow Control Devices. Covering the terms and definitions, functional specification, technical specifications, and supplier/manufacturing requirements, etc.

The API specification mentions “the user/purchaser should provide a functional specification to order products which conform to this specification”, however there is no international standards involving water-control completion design at present. 

There is a strong need for water-control in oilfield development worldwide, and mechanical watercontrol completion has become the main measure. The design of mechanical water control completion is related to the performance of oilfield development and directly affects the production of oil well. Due to the complex application conditions and the variety of mechanical water-control tools, it is difficult to carry out water-control methods and parameter design.

CNOOC have been dedicated to work on the issue for over a decade. Drafting corporation standard in 2023 and it's expected to be published by 2024. The standard proposes the principles, design, and requirements for water-control of oil and gas wells, including selection of water-control completion method, parameter design, operation requirements, and evaluation, etc. Mechanical water-control completion have been applied for over 200 wells in China offshore oilfield.

Therefore, this guideline is necessary as it guides the water-control design of oil wells and promote the long-term water-control effect. This guideline would fill the blank of standards in water-control field.