ADVERTISEMENT

Enhanced-Gel-Strength Concept Optimizes Chemical Use in Pipeline for Waxy Crude

Fig. 1—(a) Naturally flowing crude, (b) wax deposits, and (c) gelled crude in a pipeline section.

Banyu Urip crude contains 26% wax, which can lead to flow-assurance challenges in a crude pipeline exposed to lower temperatures. Injection of pour-point-depressant (PPD) chemicals has been considered an effective method to ensure flow of moderate waxy crude. For the Banyu Urip field, PPD injection was compared with other methods and found to be the best option. Nevertheless, it still contributes to approximately 20% of the operating costs. Optimization of this chemical use can bring benefits through lowering operating costs.

Introduction

The Banyu Urip Field is in East Java, Indonesia. The facilities process a stabilized crude, which is then transported through a 20-in. export pipeline to a floating storage and offloading vessel. The export pipeline is divided into two sections, a 72-km onshore section and a 23-km offshore section.

High wax content is a key characteristic of Banyu Urip crude. The stabilized crude’s wax appearance temperature is 46°C, and its pour point is 33°C (±3°C). With a lowest ambient temperature of 27°C for the onshore section and 24°C for the offshore section, a risk exists of the crude temperature dropping below the pour-point temperature during a no-flow condition, which may cause gelling in the pipeline (Fig. 1 above).

Several options were considered for a flow-assurance strategy, including continuous PPD injection, pipeline displacement, and electrical heating along the pipeline. Continuous PPD injection was seen as the best option from cost and operability perspectives. Consequently, chemical-injection facilities were installed in all the well pads for continuous PPD injection. To maintain pour point at 24°C, initial calculations required approximately 500-ppm PPD injection. At current production rates, this equates to approximately 20% of the Banyu Urip operational expenditures.

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 186295, “Application of Enhanced-Gel-Strength Concept for PPD Chemical Optimization in Banyu Urip Export Pipeline,” by Alinda Dwitawidi, ExxonMobil, prepared for the 2017 SPE/IATMI Asia Pacific Oil and Gas Conference and Exhibition, Bali, Indonesia, 17–19 October. The paper has not been peer reviewed.
...
This article is reserved for SPE members and JPT subscribers.
If you would like to continue reading,
please Sign In, JOIN SPE or Subscribe to JPT

Enhanced-Gel-Strength Concept Optimizes Chemical Use in Pipeline for Waxy Crude

01 September 2018

Volume: 70 | Issue: 9

STAY CONNECTED

Don't miss out on the latest technology delivered to your email weekly.  Sign up for the JPT newsletter.  If you are not logged in, you will receive a confirmation email that you will need to click on to confirm you want to receive the newsletter.

 

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT