Data Acquisition

Data Acquisition – How to identify the Petroleum potential of a certain area?

Oil is an abundant natural resource, but identifying the potential of an area requires complex and expensive research and studies.  The first step to assessing the potential for oil and gas accumulations in a certain region, or for the valuation of a discovery, is to organize a database with geological and geophysical information to be interpreted through means of an exploratory assessment  of the potential of a  new or an exploratory area and before commencing development or production. It is fundamental for the assessment to have plentiful and quality information, enough to make an accurate evaluation of the exploratory potential in the area.

In this acquisition and data management, state-of-the-art technology is employed to map and store the acquired data with the goal of achieving accurate assessments. These assessments represent 10% to 20% of the investment in an exploration and production project.

Data acquisition assessment is divided into the following steps: (i) search and discovery of hydrocarbons and (ii) technical and financial assessment of the exploration feasibility for the discovered accumulation. Geologists and geophysicists are involved to perform the study on the discovered elements, such as: the reservoir’s rock and its porosity, and the amount of water and sand, amongst many others. The acquired data is essential to attain estimates as to the volume to be produced. Although data acquisition assessments are critical in reducing exploration risks, they are not capable to eliminate them.

The main geological information refers to data from rocks obtained in the surface or subsurface (by mean of well profiling). These are electrical, acoustic, and radioactive profiles, geochemical analysis of possible source rocks, and biostratigraphic analysis for an appropriate stratigraphic assessment. The latter identifies the sequence of rocks in the subsurface with the goal of determining the processes and events that caused their formation, as well as the relative “life” of soil layers, amongst others.

The main geophysical information is obtained by acquiring gravimetric, magnetometric, and seismic data. They first segregate and weigh the various components found, then they examine the magnetic fields generate by these components.  These test provide more accurate results for preliminary and regional interpretations, while seismic tests are used more frequently in between the stages of for prospective exploratory opportunities and developing the discovery.

Both geological and geophysical data can be obtained by hiring specialized service providers to acquire them, or buying public domain data from the Exploration and Production Database (BDEP) at the National Agency of Petroleum, Natural Gas and Biofuel Agency (ANP). The BDEP holds all the data acquired by the Brazilian oil and gas industry. The confidentiality periods for specialized companies and providers are available in the ANP resolution # 11.

An authorization from ANP and all environmental permits from the state (terrestrial areas) or federation (maritime areas) are required in order to obtain geophysical data and drill wells.

Seismic is of primary import in the data acquisition stage since it results in more accurate information about the possibilities of a certain area previous to drilling. It consists in the propagation of sound waves which upon making contact with a land mass, return as echoes. The graphic expression of these echoes makes up the information about the composition of the subsurface mass. In the ocean, the sounds are issued from ships with thousands of receivers.

Seismic technology has significantly advanced when it comes to the detailing of the subsurface information it captures. 2D seismic data, that display big linear spacing, can be sufficient for regional or preliminary assessments. However, 3D seismic data with small linear spacing is fundamental to the accurate definition of an exploratory prospect or for development and production work in a discovery.

Seismic data might be: i) non-exclusive like SPECs, which result from assessments made by data acquisition companies, ii) property, when hired by exploration block concessionaires, and iii) promotional data, when they result from assessments made by ANP itself.

Example seismic data acquisition - photo credits: CGG

Last updated on 2015-04-29T18:22:59

Downloads


Delete this document from the cart
Clear List Download Files