Petroleum licencee holders are required to procure certain goods and services, classified under the exclusivity regime, from "Angolan Commercial Companies" (in which 100% of the share capital is held by Angolan citizens or Angolan companies) and to give preference to goods and services of "Angolan Commercial Companies" and companies incorporated in Angola ("sociedades comerciais de direito angolano"), in that order, over imported goods and services.
Previous to 2020, elegibility to benefits from preferential regimes were reserved to companies with a majority share capital held by Angolan nationals.
"Article 2
(Definitions)
For the purposes of this law, and unless otherwise expressly stated in the text, the words and expressions used herein shall have the following meaning, it being understood that the reference to the singular includes reference to the plural and vice versa: [...]
2. Foreign Associate - a corporate entity incorporated abroad and which in its capacity as foreign investor associates itself to the National Concessionaire, in any of the forms set forth in Article 14, paragraph 2.
3. National Associate – a corporate entity which is formed under Angolan law, with registered office in Angola which in such capacity associates itself to the National Concessionaire in any of the forms set forth in Article 14, paragraph 2.
[...]
Article 4 (Principle of exclusivity of National Concessionaire)
1. The National Concessionaire is Sociedade Nacional de Combustível de Angola, Empresa Pública - (Sonangol, E.P.), as the holder of mining rights.
2. Mining rights shall be granted to the National Concessionaire under the terms of Article 44.
Article 5 (Non-transferability of mining rights)
The National Concessionaire cannot transfer its mining rights, whether in all or in part and any actions to that effect shall be deemed null and void.
Article 6 (Conditions for the exercise of Petroleum Operations)
Petroleum operations may only be carried out under a prospecting license or petroleum concession in accordance with this law. 
[...]
Article 14
(Types of association and risk services agreement)
1. Subject to the prior consent of the Government, the National Concessionaire may associate with Angolan or foreign entities of recognized capacity, technical knowledge and financial capability.
2. Such association may take the following forms: (a) Corporation; (b) Consortium; (c) Production Sharing Agreement. 
3. The National Concessionaire shall also be permitted to carry out petroleum operations by means of risk services agreements.
Article 15 (Majority participation of the National Concessionaire) 
1. In the associations referred to in Article 14, subparagraphs 2(a) and (b) where the National Concessionaire holds a participating interest, such interest shall, as a rule, exceed fifty percent.
2. The Government may authorize the National Concessionaire, in duly grounded cases, to hold a participating interest lower than that established in the previous paragraph. 
[...]
Article 27
(Use of national products and services)
1. Licensees, the National Concessionaire and its associates, and any other entities which cooperate with them in carrying out Petroleum Operations shall: (a) Acquire materials, equipment, machinery and consumer goods of national production, of the same or approximately the same quality and which are available for sale and delivery in due time, at prices which are no more than ten per cent higher than the imported items including transportation and insurance costs and customs charges due; (b) Contract local service providers, to the extent to which the services they provide are similar to those available on the international market and their prices, when subject to the same tax charges, are no more than ten percent higher than the prices charged by foreign contractors for similar services.
2. For the purposes of the provisions of paragraph 1, Angolan companies shall be mandatorily consulted on the same terms as those used for consulting companies on the international market. [...]" (Law No. 10/04 regulating Petroleum Activities)
-----------------
[Presidential Decree 271/20 of 20 Octobre - New Local Content Rules for the Oil Sector [see referenced links: legal extracts not available]
Law No. 10/04 regulating Petroleum Activities
Presidential Decree 271/20 of 20 Octobre - New Local Content Rules for the Oil Sector
Order no. 127/03, of 25 November
[<a href="http://extwprlegs1.fao.org/docs/pdf/ang81903E.pdf">Law</a>],[<a href="https://lex.ao/docs/presidente-da-republica/2020/decreto-presidencial-n-o-271-20-de-20-de-outubro/">Decree</a>],[<a href="https://cms.law/en/prt/publication/new-local-content-regime-for-the-oil-sector-in-angola">Other</a>]